although your CPU is the bottle neck in your system in game i doubt you will notice the difference as the CPU does little in terms of bottle neck in games as they are so graphic orinated.
your PD will oc brilliantly i think it was a well known fact that the 820 could OC to 4.1Ghz so imagine cold cold Russia you'll get close that that.
if you read the recommend spec for crysis which is 3.0ghz single core you are well inside the bracket with a duel core @ 3.2ghz
upgrading would be nice to a C2D but not nesseray and doubt you would see an amazing gaming performance boost
your PSU wont be stable if you run a 8800gt, and especially not if you OC, it might do it for a while and then get tired and go to sleep. i would get a 530w and above perhaps 600w for the future
Q1: yes not by much
Q2: perhaps not for long
Q3: it would lower the bottleneck but you would see the improvement in PC applications rather than games
Just wondering, if my PSU "goes to sleep on me", how will it break down? I'm just asking because I'll probably wait until it breaks then buy a new PSU if it's safe. How does the PSU break? Does it break anything else? Can it damage the CPU or graphics card or any stuff if it breaks?
If that's your psu, the +12V has up to 18A. The recommended psu is 425W 28A. True to told, PCI-E 1 & 2 both draw up to 75W. Any more must be drawn through the 6-pin pci-e power cable. Stock 8800GT uses up to 105W load. Wattage-wise, your psu is ok. Amperage is a question mark.
No, it won't break. It MAY underpower your video which results in lower performance.
Best bet is get a new 450W-550W psu. For good makes & models: