1. nice but their are very inexpensive coolers out their that are WAY BETTER than the stock cooler. the cooler your CPU runs the longer it will last. Coolermaster Hyper 212+ is highly recommended. I have personal expierence with that one.
2. BIOS hands down.....
3. just bump up the FSB a lil and maybe up the voltage justtt a tad
5. its safe but i recommend you upgrade your cooling. 70*C under full load (ruining Prim95) is safe for a processor. as well as stress your overclock to see how stable it is. (24hrs without crashing is a stable overclock)
6. if you want you can step up slowly or go right at it to the 3GHz
7. woot!! i have the same PSU running my i5-661 @ 4.16GHz 24/7 and have PLENTY of power (even got it to 4.66Ghz just heat was an issue)