Not quite sure I see the point of a Military starbase... nice huge well-armed Military specialized starbase right next to my planet, NPC simply chose not to attack it and directly attacked and took the planet. Military starbase sitting RIGHT THERE, tile away, never showed up in battle view, never fired a single shot to protect anything nearby it.
So I said "huh" and went over and took out someone else who also had a very nice military starbase sitting right next to planet - I simply chose to attack planet, ignored starbase completely and it ignored me. Because I chose to attack something near by it, but not it directly (1 tile away), it did not show in battle view or take a single shot at me. Civilization was destroyed and the military starbase right next to it that failed to engage at all simply became "pirate".
If they do not defend any planet nearby them...only themselves...then what is their point? Why wouldn't everyone simply do what just happened and wave politely as we stroll by, granting them a lovely view of a planet slaughter?
There are lots of really cool sounding Military Starbase upgrades my base had equipped with, which it then did nothing whatever with and didn't even show up in battle.
I feel as if all Military star-bases should have an automatic bonus to its radius. On anything above a small map they are kinda useless as you can avoid them. By having a bigger radius you could literally make a wall of bases on your border which i think would be cool. Kinda like in startrek where they have a border defense detection grid.
And i haven't really build them so im not sure if they already do. But would be really cool to have some "system defense" techs that automatically per turn slightly damage all enemy ships in its radius. Kinda like a long distance weapons platforms. that would make them more of a target. Also would be cool to have modules that boosts all planets resistance by X%. That way if you invest in them not only would they pose a threat from being able to damage ships for a short distance, they become a meaningful defense to destroy before you invade a planet.
if a base also gives a 50% bonus to resistance to planets, there would be more of an incentive to destroy it first before you tried to take a planet. And as i said before if the radius was larger, not only could you chain them together easier, but it would mean you still could build economic bases and such near your planets. As it is atm, most of the time the eco base is always the better option. Everywhere else is empty space so why would you even bother when as you said they can just fly right past them. On that note, would be cool like in galciv 2 if you could add warp inhibitors on them that reduce the speed of all ships in its radius. (actually i have a feeling that last one is already there, but im not sure i didn't check)
There are lots of really cool sounding Military Starbase upgrades my base had equipped with, which it then did nothing whatever with and didn't even show up in battle.
Edit: Most of the upgrades simply boost the damage and shields etc of ships in its area of effect. which sounds good in theory but you really need the base in a good spot to make it worth it, besides i have noticed most the time just adding one extra ship to a fleet is just as good as some of the bonuses.. tho i really have not built many as i just avoid them most the time.. so maybe they are better then im thinking.
Also side note, Stardock is going to be making either an DLC or add it in the expansion, a fulled redone and upgraded starbase system. Where they have already said they want to address a lot of the problems people have, and hopefully that is when they will also add the Star base designer like the ship designer/ 