Electrical sounds are indeed very bad.
Yet, I dont think that you should throw away stuff that does still work fine.
Optical drives are cheap [read- built to a price, not a quality] ...so not worth hanging on to....really.
That does not mean you have to dump them before they fail. Newer drives dont offer much about older ones, too.
I also want to point out, that those drives can live for 10 years and more, especially if not used 8 hours a day, which is rare.
Power supplies have a finite life...and if old will likely be underpowered.
It is usually a good idea to buy quality power supply instead of dirt cheap ones.
Also in your case, make sure that it is NOT your PSU who caused electric trouble... and if in doubt.... remove it.
I would not go to high in wattage.... with most PC hardware getting much more energy efficient, you rarely will need an owerpowered PSU.
Case 'may' be OK, but a new one means there's a container left for the old bits.....
It is nice if you have money to burn, but personally I would not use a 60 - 100 € case as a trash can.
Video cards....get tired [fan dirt] and are soon superceded by something cheaper/better....
You know you can clean fans with pressurized air?
Also make sure that your CPU and GPU are a match.... respectivly find out what is slowing down your system and consider replacing that first.
Or make sure that should you go to buy your new high end graphic card, that your processor is up to the task feeding it.
Video cards....get tired [fan dirt] and are soon superceded by something cheaper/better....
And hard drives.... they get old...but can be relegated to storage/backup while the real action [OS] goes on a SSD instead.
Never trow away storage space..... you will need it in time, believe me.
Better invest in backup storage..... yes... even a 2 week old hard disk or SSD can fail fataly.
As for SSDs, they are awesome for speed, but they are still much more expensive than hard disk drives of similar capacity. And while they dont have any mechanical parts who wear, the memory itself does wear with every write to it. The implemented wear leveling algorithm does mitigate drive encryption, although that of course may be of no concern for you.
Generally speaking, it is of course awesome to buy or build a brand new rig with the latest and best hardware available. Doing so however means that you will burn a lot of money in the process.... for perfomance that will be topped by medium range systems 6 month later for half the cost.
If you can spare that money, awesome. If not.... consider upgrading only CPU, RAM and maybe graphic card, depending on what is the bottleneck.
Usually the medium price range offers to best long term deal.... you dont pay the premium "Must have that now" price but also avoid the low end "upgrade every 6 month because your upgrade gets to slow within that time frame".
And get rid of Vista... it transforms 4 Ghz Quad Cores into 500 Mhz pentium IIIs with 64 MB of RAM.