Sorry but your off your head...
Theres no way a low power integrated gpu can assist a proper gaming grade GPU in any shape or form in any demanding rendering situation - infact quite the opposite it would hold a high end GPU back in ANY 3D rendering if you forced them to coop. You might wanna not be sucked in by the hype sometimes...
As to the CPU thing - I could quite simply say "people" have told me and it would be as valid as what you've said

in reality overclocks where you don't have to adjust the vcore aren't likely to show any increased degredation within the useful life of the chip - and the i7 and core 2 line can manage some fairly impressive overclocks on stock voltage alone.
I'm sorry but in the hands of any enthusiast the i7 will CRUSH the Phenom II - and if your the average every day joe kinda user then it doesn't make much odds which you buy so you might as well go for the cheapest as you won't be getting the most from either chip.