It's obviously not reading the +12V correctly otherwise I doubt the PC would be working.
If it really is around 8V then something is seriously wrong.
Never heard of an NTK 500W Gamer PSU.
How much did that cost?
And how have you ended up with 6GB of RAM on a Core 2 system?
I'll take your word for it.
Normal is having 2 identical sticks.
You can't. It's either working correctly or it isn't.
If you PC runs properly then I'd say it's a mistake with the program.
Is this "Turbo Key"?
I suppose the answer is as much as it will take while still running stabily.