DIY dust filters... Installed them last night. Made from cut up surgical masks :P Time will tell how they perform.
Ghetto or no? Methinks the tape is a nice touch :D
EDIT: Sorry for the huge pictures! How do I make em smaller?
EDIT 2: Got it, I think.
I'd say 85-90 degrees at load is quite high for your chip. Are you sure you haven't left the voltage to be auto-regulated by the mobo? Decreasing Vcore gave me around a 7 degree drop on my 3570 (non-k).
It's possible that the old PSU damaged something, though it's not very likely. The PSU usually dies itself before it damages PC components, if it's a quality PSU. But, like the others said, you should acquire another rig to test the new PSU on.
I bought a faulty power supply once for testing...
Yep, like everyone else said, there's no point in adding another layer of conductive material. Even if it does have a higher conductivity than the thermal pads, it will provide no benefit at all, since you're just increasing the distance the heat has to travel.