New to GalCiv

At the start, you need to focus on population growth.  Your initial colonies will have 250M colonists and produce very little tax income.  Go for low taxes in the beginning so that your colonies will be happier and grow faster (green approval ratings are best for growth).

Don't build anything that costs maintenance unless you really need it and always aim to run your production slider at close to 100%, unless that would make you go into deficit.  When you have your production slider at 100%, you're getting the maximum from factories and labs that you can, considering that maintenance is the same no matter where the slider sits.

Entertainment technology is a good one to do if you haven't been able to snag any morale resources, because it allows for quicker population recovery, which means less chance of getting half-filled transports.

Manufacturing and Research techs allow you to access better factories and labs, but until you have a bigger economy you're not going to be able to fill lots of tiles with them.  Dip into these techs when you have money coming in but your old factories and labs just won't cut it any more.

Specialise your planets.  A high-population world with lots of economy buildings will help to fund production on a planet which has lots of factories or labs.

To go for a military win, you need an economy which will support the maintenance that your fleet incurs, logistics so that your fleets remain competitive, weapons technology, larger ships and Planetary Invasion.  It doesn't hurt to research propulsion too but unless your opponents have a speed edge you don't need it to start war.

To go for an early rush, you want to stop colonising when you have a fair share of planets and aim to take the rest by force.  You want to be attacking the likes of the Drengin or Yor before they build up their fleets.  Your fighters don't need to be better than theirs, just cheaper and more numerous.  Super Warrior is a great pick because if your ships destroy their opponents in the first round when they attack, those opponents don't get a single shot on your ships, and Super Dominator can give you an extra bunch of ships to increase your numbers.

With an early rush you concentrate on taking high-quality planets close to your space, as these have more tiles which can be used to power your economy.  But as with the colony rush, the more new planets you conquer, the more maintenance you have to pay.  So if there are structures on those new planets that you don't need, get rid of them, unless they're more advanced than what you have on your other planets.  The aim here is to cripple an opponent.  If you get too ambitious, someone else could join in on their side, and all your hard work could be undone.  It would be nice if you could take all their planets, but even if you just take a few you're slowing their economy and giving them fewer tiles to put factories and labs on, and giving yourself more space for economy or production.

To go for a build-up war, you need to keep the other guys in the game at war for a while.  Depending on who you're bribing to go to war with whom, this can cost a bit of money, so a focus on economy is vital.  Don't get the Drengin into too many wars, as each time they war they get free corvettes.  Diplomacy techs will improve your ability to get what you want for less credits.  Super Diplomacy is a good ability to take, as is Super Manipulator.  While they're at war, you keep researching better weapons, but don't build lots of ships.  Rather, keep the fleet you have built up-to-date with the latest advances.  You will need plenty of frigates (medium hull ships) and not of the cheap variety.  Also, while wars are raging, see if you can grab those military resources, as these will significantly boost your attack strength.

A build-up war is a devastating backstab with everything you've built up.  That stronger race which you bribed to go to war with a weaker race?  That's who you're going to attack, because once they're out of the way the other guy is easy pickings.  Grab as many planets as fast as you can, or failing that at least decimate their orbital defences, allowing the weaker race to snag any planets you can't capture.  You're aiming to make a clean sweep here, after defeating the strongest the other races are basically roadkill to be cleaned up.

To go for a death-ray war, you must avoid winning by any of the other ways to win, and you must keep your opponents from doing the same, and you must be ahead in the tech race.  You need the big guns at the end of one particular weapons technology tree (hence the name, death-ray war).  Defence technologies are useful in that they will allow your ships to take more punishment, but they're not essential.  You will however need big ships that can pack lots of weapons and take a fair beating.  Super Annihilator is a useful ability because it removes the need for troop transports.

A death-ray war is where you upgrade as many of your ships as possible to use the biggest and nastiest weapons, and mow down your opponents' fleets before they get their hands on the same.  So lots of spare credits is a must, but speed of research is also important.  Because the other races will try and get their own Death Ray, you need to go to war with any of them which are close to that goal, and conquer their planets as quickly as possible, making their research progressively slower.  It won't matter if you bombard those planets with mass drivers, since you're only hanging onto them to win, and the mass drivers invasion tactic is very economical in terms of troops used.  The races that you didn't declare war on right away will have no chance against your fleets, so as soon as you have transports rolling, invade them too.

No matter when in the game you start fighting, you need to have some kind of edge.  In an early war, it's numbers and surprise.  In a build-up war it's speed and strength of attack.  In a death-ray war it's being first (and making sure nobody else crosses the finish line).

To avoid being extorted so much, you just need to have the biggest and nastiest fleet.  It doesn't have to be high-tech, it just needs to be a little more menacing than your opponent's fleet.  You can see how you're doing in this regard by looking at the military graph.  You don't want to build too large a fleet until you're ready to attack someone, because it costs maintenance.  When new ship technologies have been researched, design new ships that use less guns but still give a bit more firepower.  For example, instead of six lasers (6 Beam Attack), fit four particle beams (8 Beam Attack).  This means ship maintenance doesn't go up too drastically.  You can add more guns later on.

Don't put too many weapons or other modules on tiny and small hulls unless you have the production to churn them expensive fighters one per turn.  They usually end up being destroyed first, reducing your firepower in the second and subsequent rounds of fleet combat.  If you're expecting to go up against fleets of mostly frigates, fleets of your own (medium hull) frigates will likely fare better than fighters.

Alternatively, as soon as the first extortion demand comes in, with you declining, immediately start a bribing campaign to get all the other races into a mesh of wars.

I might suggest converting the miner on turn 1 to a colony ship and NOT colonizing the marginal planet in your home system.  As MK recommended above, do less building on the new planets until their population grows for taxes.  That means pick one or two to do some building on for expansion or for use of juicy bonus tiles, but not much more.  To max early pop growth, try to adjust taxes to keep approval at 100%.  To max the spending slider while keeping taxes low enough to maintain 100% approval means verrry little rush buying is possible.

Perhaps focus on the empire-wide bonus techs as the highest early research priority.  I like grabbing the diplo translators to help with the early bribing.  You do NOT need weapon techs to bribe others into wars.  Many times, I skip the first levels of weapon and defense techs by trades even with minors.

BTW, I like to grab sensors early to build cargo survey ships for anomaly harvesting.  If the others are in wars, their flagship survey ships get killed off, and the AI never builds more.  Also, a constructor that builds a distant base extends the survey range fairly cheaply in that direction.

This is great stuff ya'all.  I'm liking what I'm hearing.  Seems like ya'all have really played this a lot and figured out how to maneuver through tons of different situations using various means.  I'll give some of these ideas a go later on and let you know how it goes.

Some additional easy recommendations:

1) If you really feel you need to rush-buy a colony ship (as it would take ages to complete), don't buy it straight away but when it's already half built. That makes a huge difference in price. Always explore the cheapest rush-buying option (cheapest as in lowest total cost)

2) Don't build starports on every planet. In line with the recommendations above, in a small/medium galaxy I start building my homeworld and 2-3 other decent quality planets (1-2 specialized in production, 1 in research) and leave the rest empty until the population yields a decent tax income.
And indeed, specialize your planets. A few purely manufacturing planets will be able to quickly increase your fleet whenever needed, rather than having a ton of planets that require dozens of weeks to get a ship out.

3) I always keep an eye on the military rating of the other races. As soon as one goes above zero, I don't wait long before researching some basic weapon technologies. In addition I try to get to small hulls as soon as possible, and medium hulls as soon as that tech doesn't require too much time. Medium hulls + fairly basic weapons will go a long way.

4) I don't see you mentioning tech trading (i.e. exchanging technology, influence points, cash with the AI in return for their technologies). Do this often, this is also how the AIs manage to develop fast. They don't research all techs themselves but actively trade.
Never trade any technology that gives the AI a diplomatic bonus (as this will make your future trades harder) and try to get relatively cheap techs in return, especially the ones that give you X% bonus to production, econ, morale, ...
Also nice to get are any techs that are unique to the AI race (indicated with a * next to them in the trade screen) as you won't be able to research those yourself unless you have the same tech tree as that race.

5) Influence points should only be traded with less than 1000 at a time (somehow the AI sees some value in buying 999 IP, but as of 1000 considers them to be worthless). Feel free to trade those for small amounts of cash or technology early on, it's often worth losing some voting power for in the united planet councils.

Questions for you:

How do you accrue IP?  I never paid that much attention to them, but I seem to recall never having more than one at any given time.

There are race-specific techs?  Isn't that only in Twilight of the Arnor?  I'm playing Dark Avatar, don't even own TotA, and when I was deciding if I had enough cash to buy all three, I seem to remember reading about race-specific tech trees in the TA Features List.

Questions for anyone:

Is there a certain amount of population or Income that ya'all wait until before starting to, or heavily, developing a planet?

Is there a stop-point for the maxing production/minimizing taxes thing, or do you just want to always be trying to play on the razors edge for best benefit?  I say trying because naturally I assume there are exceptions to the rule, if the above is true.  I also assume there's always a time to up the taxes, since once you have population, taxes will actually be worthwhile at some point.

I'm gonna get on a starting a game tonight to try this stuff out and let ya'all know how I do.  Haven't had time to play as me and a pal found a real gem of a game with lots of nostalgia value that we've been re-exploring in depth now that we're older.  Fortunately for GalCiv, I've got tonight and tomorrow to play around with trying to actually be good at the game.  =P

How soon to start building economy buildings... wait until your population is high enough that the economy buildings will turn a profit after their maintenance is paid.

How soon to start building factories or labs... if you're running the slider at 100% and still have a surplus of credits each week, and you don't have any labs or factories being built, build as many as you can maintain and pay for.  Although factories and labs cost a set maintenance each week, what they produce also costs credits (Military, Social and Research expenses) although both only produce a fraction of their rated output, according to how your military, social and research sliders sit, and you only pay for the fraction of output produced.

When most of your colonies have reached maximum population, you can pretty much raise taxes as high as you want.  But if you go nuts, populations will start declining.  Raise taxes to 29%, 39%, 49% (and so on) and take a look at all the approval ratings in the colony list.  Raising taxes one extra point to 30%, 40%, 50% (and so on) won't gain any more tax, but will result in a drop in approval.

If your colonies are still developing but you really need to raise some credits, take your survey ship off automatic and send it to asteroid or planetoid anomalies in particular, because ship graveyards generally enhance the survey ship, civ graveyards sometimes help with your research project, and wormholes just send it to a random point in the galaxy.  The other ones sometimes net you credits.  While you're doing this, you should find you'll be able to keep your economy going even if you're running with a slight loss (so raise taxes, but only to reduce your loss-making).

If you really have no choice but to reduce production, remember that you will then be getting a fraction of a fraction of a lab or factory's output.  So concentrate only on those things you need produced.  If you need to do things differently on one or two particular colonies, you can use focus to shift attention to military, social or research.

Okay, so starting a game...  Used the handy CTRL-N function to get a slightly stronger start...  Because my first two starts were so far separated from the rest of the galaxy, each time I got colony ships near a decent planet, it got sniped out from under me and I was left with just the two around my home star.

Here's the basic rundown of my game at present:

Habitable Planets, Number of Planets, Number of Stars: Common

Star Clusters: Tight

Anomalies and Number of Asteroids: Abundant

Technology Rate: Normal

Minor Races: Random  (I really like this.)

All Victories Enabled, Mega Events and Super Abilities Enabled.

Map Size: Medium

Opponents: Nine  (I'm looking for a tougher game here, part of why I lose probably, but I haven't gotten sick of it yet.)

Race: Minmatar  (Yeah, I know, I ate EVEO's race...  I love 'em though, so I had to make them the way I wanted to make them.)

Racial Abilities:  Economics +30, Luck +25, Loyalty +20, Research +20, Morale +20, Population Growth +5

Super Power: Adapter

Government: Universalists  (I really enjoy the concept of this government, even if it's not the best by a long shot.)

Starting Technologies: Hyperdrive, Universal Translators (Xeno Communications prereq), Stellar Cartography, Xeno Research, Xeno Engineering

Turn 1:  Okay not restarting this time, definitely got a decent enough start.  Homeworld's pretty damn good.  3 Special Tiles.  Not as good as the start with x2 100% Industry Tiles and x2 100% Farm Tiles and x1 700% Research Tile, but that would've just been too easy anyway.  x1 100% Research and x2 100% Farm tiles...  Okay, only one of those I'm even gonna make use of right now, but that's okay.  Set the miner to-...  Right, upgrade the miner, okay, upgrading...  Colony ship next turn, cool...  Okay, ignore the C4 Planet....  Right, then I guess I'll see if I can get a glimpse of one of these nearby stars first...

Would ya look at that.  Super Adapter's already gonna come in handy.  An Aquatic World...  Only C4...  Hmmm...  Tough sell...  Well, 3 worlds is better than two, so I'll go ahead and grab it.  And besides, population is population is taxes.

Turns 2-5:  Okay, not much goin' on here.  Picked up the water-world...  Exploring...  Exploring...  HOLY CRAP A CLASS 18!  In the immortal words of Sasha from 2012:  "Come on baby, move your big ass for Sasha!"

Observations thus far:  I'm glad I ignored that first free world.

Turns 5-10:  Okay, wow...  This has to be an imba start...  A Class 11 just 3 tiles away from the 18!  Wait a couple turns and then fast-buy that Colony Ship.  Now move move move!

Observations thus far:  I should've ignored that water world.

Turns 10-20:  Okay, jeez...  Like 4 Toxic worlds, one of them with the same star as the C18...  Only two worth getting that I can see.  C8 and C7.  C6 Aquatic World too.  Dear Lord...  I hope the Iconians don't mind that I'm settling RIGHT NEXT TO THEM...  Crap.  Glad I already picked up basic Rail Guns.

Observation:  I am REALLY glad I took Super Adapter.

Turns 20-30:  Fast buy that next Colony Ship for like 300 creds...  Not too bad...  Despite hemorrhaging money at about -65/turn...  I've still got a couple grand left...  I'll be okay...  I hope...  No way I'm gonna fast-buy to get all these worlds though.  Guess I'm doin' it the old fashioned way...  Good thing my factory and Xeno Lab finished forever ago.  Gonna have to fix my economy soon though...

Final Summary of my game thus far:

Total Habitable Worlds Found: 13 not counting the free world.

Total Inhabited: Homeworld, 1 C18, 1 C11

Soon to be (Hopefully, but doubt I'll get 'em all,): 1 C11, 1 C8, 3 x C7, 1 C6

Later to be (Again, hopefully,): 1 C5, 2 x C4.  (3 C4's if you count my free world.)

I can't say I'm thrilled at the idea of losing credits like this...  But hell, I've got a ton of worlds now...  A C4, C11, C18, and working on picking up the 3 C's 6, 7 and 8 in the area...  Then I think I'll snag the one at my home star...  Just gonna ignore that C1 I found.  The population doesn't grow fast enough to off-set the money I'm losing, particularly with the fast-buying...  That may be the problem here.  Gonna be on the edge of self-destructing for a while I guess...  I can handle that.  I do better in the clutch anyway.

Found the Drengin, Yor, and Korath already...  Before the Iconians actually...  Terrans, Altarians, Iconians, and Korx as well...  Still missing a pair.  I oughta learn more about the Iconians and Korx...  Can't believe I met almost all of them before I met the Iconians...  I mean, I have influnce rings turned on and all, so I know where they are anyway without Blind Exploration enabled, but still, it's a little shocking.

Looks like I'm gonna be a little light on the Anomalies this game.  Trying to keep tabs on what worlds I'm likely to get isn't easy.  Not so bad though.  At all, really.  I mean, I'll have a ridiculous population by the time I'm done with this...  Only problem I'm likely to have this game after I hopefully fix my eco is gonna be morale, and so far I've been keeping that at 100%...  Glad I've been microing that tax rate every turn and didn't just hit 0% right from the get-go...  This economy is bad enough...  If I can fix those two things, then this game is gonna be HELLA skewed in my favor...

Edit:  Well crap...  Exactly what I was afraid of...  The Korx sniped my free world from me...  Lovely.

I've added my replies in blue, between your questions:
Questions for you:

How do you accrue IP?  I never paid that much attention to them, but I seem to recall never having more than one at any given time.

They accrue automatically based on your influence in each sector. At the start of a year you'll have zero, by the end of the year they should have grown.

There are race-specific techs?  Isn't that only in Twilight of the Arnor?  I'm playing Dark Avatar, don't even own TotA, and when I was deciding if I had enough cash to buy all three, I seem to remember reading about race-specific tech trees in the TA Features List.

Oops sorry, missed that in your first post. Indeed that's only TOA...

Questions for anyone:

Is there a certain amount of population or Income that ya'all wait until before starting to, or heavily, developing a planet?

I agree with MarvinKosh, it only makes sense to build econ buildings if their additional income will be higher than their maintenance cost. However be aware that building on a newly colonized planet will cost you 4-5 bc per week compared to not building anything.

Is there a stop-point for the maxing production/minimizing taxes thing, or do you just want to always be trying to play on the razors edge for best benefit?  I say trying because naturally I assume there are exceptions to the rule, if the above is true.  I also assume there's always a time to up the taxes, since once you have population, taxes will actually be worthwhile at some point.

Correct, once more / most planets reach their maximum population it's time to increase taxes since population growth becomes marginal at that point. Practically speaking I'll usually be forced to increase taxes at some point, when I see that my current cash reserves will only allow me to continue my spend deficit for ~30 more weeks. (the 30 is not a fixed value but some sort of safe buffer, at that moment I'll decide to increase taxes and reduce my weekly deficit to something more sustainable)

On your current game:
1) I would recommend not to rush-buy anymore and in fact to rush-buy a lot less in future games. Instead of savings a few weeks by rush-buying, research or trade for engine technologies to speeden up your colony ships. Once you have access to more advanced engines, you can consider modifying the design, putting stronger or more engines on your colony ships.

2) Don't worry about that "free world" PQ4 planet next to your home planet. Right now developing it is costing the Korx money while the returns of such a planet are small

30+ Turns Later....

Wow...  Like...  Well...  How...  Wow........

So I've been basically running this game on auto-pilot more or less.  Pretty much, I'm just reacting to whatever seems to happen in the galaxy.  If I see missiles, I get missile defense.  If I see Freighters, I get Trade.  If I see resources, I get Constructors.  If I see Influence eating my planets, I get Constructors.  If I see I'm not number one in military, I build a ship or three.

And somewhere along the way, the checkbook started balancing itself out.  I mean, sure, I turned down the production and turned up the taxes when I was at -155/turn with only 500 in the bank...  But I was still deficit spending at about -30/turn...  And then, like magic, the number turned green...  I'm not really sure why...  Most of my planets still read red in the Civ Manager, and the only ones that seem to be making any impact are the ones that're getting taxes from growing...  But I went from 65% Production and 40% Taxes with 88% approval to 15% Taxes and 95% Production...  With 88% Approval Rating a few turns later...  There was a point where no matter how low I set it I couldn't get approval above 99%, so I stopped trying to keep it maxed and decided anything above 80 or 85 would have to do, and thus I think I answered one of my own questions; "When do you stop minimizing Taxes/Maximizing Production?"  Well, you don't ever stop maximizing production for more than a little while it seems, but you bump up taxes when your eco won't support it anymore...  And then the rest fixes itself...  It's like seeing David Blaine as a kid...

I figured out the IP problem too.  The trade screen shows trading IP in increments of one, therefore you only ever see one IP there, despite having more like 30K...  And here I thought they were really valuable somehow...

Now my only problem is techs.  I'm pretty damn sure I'm still ahead, thanks to having 2 planets with +Research tiles, but I keep running into this problem...  The other leaders never seem to want anything that I have, unless it's a Colonization tech, and I think ya'all can understand being iffy about giving those to anyone who doesn't have them already.  Obviously this means I can't trade tech-for-tech, and IP doesn't seem to help...  Tried to trade everyone every single IP I had on top of a tech for just one of theirs and they refused...  That's even with having a better diplomacy than anyone else except for the Terrans, though I'm not sure of the margins.

The Drengin settled in next to me and lost their world to me via culture.  It was weird.  At the same time, I have yet to get Minmata II back from the Korx, despite being in the heart of my cultural vortex.  Makes me worry.  I could probably declare war on them without any losses...  But I've thought that before and then suddenly been overwhelmed by Frigates wielding 16 guns...  I'm going to tread carefully on this one...

I think ya'all just trained me in the art of GalCiv.  I'm officially a rookie now!  (Read: One step up from, 'OMG THIS GAME IS SO HARD I QUIT!')  Thanks very much for the advice, it seems to be paying in spades.  Now, let's see if I can't crush some weaklings!

Edit:  I gotta remember to refresh the page before I post...  Thanks for the answers Noctilucus!

A few other things that may prove helpful.

Your basic Colony Ship is three Basic life Support modules, an original Hyperdrive module, and a colony module, on a cargo hull.  While this suits those times when you need to burn quickly to someplace else and settle, it is a bit expensive if you're planning to settle a planet three squares away. Use the Ship Designer to create yourself a barebones Colony Ship, no Hyperdrive module, maybe one of the Life Support modules.  Your starports will be able to build this one quicker.  If you get really far ahead with research into Miniaturisation, you will be able to do a barebones Colony Ship on a small hull.  The saving isn't much, but if it shaves a turn off your production time, or several hundred bc off your rush cost, it's worth doing.  You can do the same trick with Space Miners and Constructors.  You tend not to want to make a barebones Freighter, because they work better if they have more engines and can get to their destination faster.

If you research down propulsion you can replace the Hyperdrive module with an Ion Engine, which both takes up less space and is a bit cheaper.  When you re-design something which is currently being produced (as opposed to starting a new design from scratch or picking from the templates) the starports will use the newer design.

If you research Soil Enhancement, Habitat Improvement and Terraforming, some of the worlds you have will improve their class and give you more tiles to work with.  Therefore, when you see a planet with a low PQ (Planet Quality) don't forget that it might eventually have room to host fifteen labs.  But you don't have to colonise them all, especially if they're in your influence; because what could be better than having aliens do all the terraforming for you, just in time for it to flip to your control?

@MK:

I've actually thought about designing my own Colony and Constructor Ships, but could never be bothered.  At least at my difficulty, it's not really an issue.  Knew about the Enhancement projects too.  Depending on my starting techs and galactic circumstances, Soil Enhancement is usually an early priority for me.

I think Impulse and Warp Drive techs are also worth +1 movement to...  Well, everything.  I could be mistaken, might just be the flag-ship...  I could never be bothered to actually check, and I generally put Impulse Drives on everything when I get 'em Mark III.

Status:

Game was going great until my Comp crashed.  No real wars until recently.  Yor got a Shard of the Telenanth, and they're right next to me after having taken a large chunk of the Iconian worlds, so I figured I should kill them before they got too strong.  I'd say it's turn 250-ish.  I don't actually know how to tell, seeing as how I never paid any attention to what month/year the first turn was.  Thinkin' it might actually be time to bump up the difficulty now that I know how to play.  Still gonna finish this game and see what happens though.  Might still be more to learn before I'm ready to move up.  Hope I have a good auto-save.

Questions:

So it seems to me that the key to a well-functioning fleet is a somewhat cheap and massable ship, massed up of course, with some of the top end ships you can create sprinkled in for that extra oomph.  Any thoughts/suggestions on fleet compositions?

What do ya'all call small-hull sized ships here?  I know you call Mediums Frigates, but that's about it.  I assume Large is Cruiser and Huge is Battleship, but I'm probably wrong, so if I am, I'd like to know what ya'all call those too.  =P

Any tips on Large-Hull ship design, besides the *obvious?  (*Pile on the guns.)

How do ya'all decide how much Attack:Defense to put on a ship?  Before this game, I was generally going 3:1, Attack:Defense, but I've been doing it more like 10:1 this game.  Lose more ships, but kill more too, and I find it to be cheaper in the long run, at least if you can out-produce your opponent for a while.  If not, I'd assume it'd be more cost-effective to make each ship as staunch and scrappy as ya can.

Fleet design is very individualistic. It's possible to crunch the numbers and come up with an "ideal" fleet for a given technology level, but I and a lot of other players build fleets to serve our needs without worrying to much about whether it's the "best" fleet possible. Generally I use a mixed set of hull sizes and usually have at least one fast raider-type ship.

As far as hull names, that's also individualistic. The AI's naming system is: Tiny - Fighter, Small - Heavy Fighter (though it also has Defenders and Escorts) Medium - Frigate (though it also calls some Cruisers), Large - Battleship, and Huge - Dreadnought. Most players use their own naming convention; in fact mine varies from game to game. A common one is WWII-era naval classes, with small hulls as destroyers since they aren't that fighter-like.

Well, this proves it.  Ya'all are the masters of your game.  I won, finally.

My auto-save was in a pretty decent place.  I only lost maybe 15 turns, not enough to really even phase me that far in.

Took me another 500+ turns, but I did it.  Didn't get the Conquest I was looking for, won on Culture after eliminating the Krynn and Drengin, but I'm glad it turned out that way, and in my eyes I still won my Conquest.

See, I didn't wanna kill the Terrans, Torians, or Drath, for a few reasons.  First, they all held out against the might of the Drengin, hanging on by a thread and still somehow coming out alive.  The Torians even lost Toria IV, their only other world, on at least a dozen occasions.  I know this because it kept culture-flipping back to them.  The Terrans never really directly engaged the Drengin, but their maneuverings kept them out of the line of fire long enough to survive.  And the Drath must've killed hundreds of Drengin ships...  Plus, I was still feeling bad about one of my trade workers having killed Draken.

All-in-all, I gotta say, it was satisfying, and probably would've been less-so if I'd had to do the cleanup of killing the remaining three races.  Winning on Culture via Conquest doesn't bother me in the slightest.

With that, I bring before the Masters my final questions.

How the hell do ya'all deal with such a massive empire?  By the end of the game, my Colony Screen was more than a full page long.  More than once I had to step away and have a cup of coffee just to get my head on straight.

I'm thinking of bumping up the difficulty, and on Normal-sized maps, I will from now on...  But I want an even more epic game than that.  Two days to complete a 4x game just isn't my style.  I need something that's gonna take a week.  With that in mind, would upping both the Difficulty and Size potentially make it too hard?  I realize the Empire's will get even bigger, and it's already making my head spin to manage it on a Normal Sized map, but I can handle that with patience and coffee.  I'll probably try it anyway regardless of what ya'all say though, just to get my feet wet.

This game was against sub-normal AI's.  How much more difficult would it be if I kicked up their intelligence a notch?

Just a few quick notes:

Not really. Large maps aren't any harder then small ones, and take quite a while longer. I generally recommend lowering the planet count on larger maps to cut down on micromanaging.

It's hard to say, but "Tough" is actually the game's "Normal", that is, the difficulty on which you and the AI have equal abilities. I generally find it challenging enough for myself.

Some answers to your questions; even though the game is over I hope they will be useful in your future games...

On influence points: due to a quirk in the way trading works, the AI will find some value in anything up to 999 influence points at a time. However if you offer them 1000 or more in 1 go, they will see no value in those.
Nothing keeps you from selling 999 IP, staying in the trade screen, selling 999 more, etc.
Mind you, they probably only offer 100 - 200 bc for every 999 influence points, but still it can help.

Honestly I rarely bother with defense (unless I happen to have the technology and some spare room on my ship where I can't add more offensive weapons)
1) It takes away research focus from stronger offensive weapons and/or miniaturization tech and/or bigger hulls
2) Defense works well against the right weapons but X defense is usually taking up more space than X offense of the same type. In addition, against weapons of the other types, defense only counts as the square root (e.g. 10 shields will only result in 3.16 defense against missiles)

Outside of weapons, don't neglect which engines you put on your ships. Too advanced and they'll be very costly; too simple and your fleet might take ages to arrive. For planet defenders, you can even drop the engines (or have the most basic ones as long as they don't take a lot of hull space). For attackers, ensure they have a decent speed.
You can also use the attacker type to defend nearby planets that wouldn't have enough ships in orbit to withstand an attack.
For the bulk of your defenders, consider how much they cost to build and their maintenance cost, so don't use very expensive components if they don't bring a really big increase in offense/defense.

To keep things manageable, sorting your planets in the colony screen usually helps a lot. I often sort based on which buildings / ships I'm building so that I don't have to scroll through planets that aren't building anything.
For really big universes you'll need to use a planetary governor but I never went into that myself as I prefer small/medium galaxies...

P.S. congratulations on your first victory!

I really like the initial exploration/expansion phase, so I tend towards larger maps and drop the major AI count down one or two from the max number.

Those two steps combine to give me generally enough time to explore some and colonize a few planets before encountering others.

You can rename your colonies (even after initial colonisation) to help you manage them.  So for example, you could name economic planets anything starting with E, research colonies starting with R, and shipbuilding planets starting with S.  Also, if you have lots of colonies building ships, it can help to put rally points where you want ships to go.  Colonies can be set to send new ships to those rally points (it's the yellow icon on the planet's picture when you click on the planet).

The governor screen lets you tell all colonies sending ships to a particular rally point to now send them to a different rally point, for example.  Of course you could just move the existing rally point, too.

Larger maps take longer but aren't much different in difficulty.  Instead of one quick colony rush, there is a long period over which colonies are snapped up as range allows.  You may find that your military ships are stretched a bit thin if you try and colonise everything you can reach, because now it takes longer for them to get somewhere if they're needed.  On a larger map you will get great use out of the Speed ability if you pick it for your race.

The AI definitely gets better as you crank up the difficulty, when you go all the way up to Challenging or Tough it uses all the tricks that it knows.  So be prepared to adjust your tactics.

Speaking of the governor screen, that's also where you can do mass-changes to which ships are being built.
As an example: imagine you recently developed a bigger hull. With 1 click you can have all planets that are building a certain ship type, switch to your new ship type. That helps a great deal, rather than having to check dozens of planets individually.

I use the Colony Management and Governor Screens a lot actually.  Rally points, not so much, unless I have a reason, like a war going on...  Those video tutorials actually have a few helpful pieces of info.

So, I bumped it up to normal, playing Large maps...  Back to getting my ass handed to me...  Heh.  I'm pretty sure I know why though, bad tech choices.  Gonna try without letting my greed get the better of me and see how I do then.

Do the Thalan's just ALWAYS grow to astronomical sizes if you don't stop them in the early game?  I mean jeez, I can get like 100-150 turns in and they'll have influence on like half the galaxy and a bazillion ships...  It's scary.

I would grab speed, but I think that my current abilities along with my Government choice synergize really well, don't wanna screw with that.

Wonky stuff with the new Elemental patch, so it's back to GalCiv for a while.

Yes. The Thalans (and Torians as well) have always colonized like mad to form what's called "the pink blob of doom". Back in DL they sometimes fell apart and seemingly slept through the game, but in TA it's all colony rush, all the time.

Don't forget that you can bribe other races into attacking the Thalans when they're still manageable in size

For my games where Thalans don't play, Humans are in the top of colonizing madness, with Torians of course.