Just a quick update, while (1) taking the machine apart and using the blow-dryer on NVidia chip brought the machine to life initially, it didn't last. In about 2 months time, the blank screen play started again. Repeated (1), and the problem went away the second time.
Though this time I figured I should try to change the logic board and around $300 price from acendtech seemed more reasonable that the $799. Replacement went well and everything appeared to be in order. In about 2 weeks time, the funny flashing RGB pixels started to appear randomly on the screen, and the problem got worse to the point where the screen freeze becomes a fairly regular occurrence. The only recourse at this point is to perform the hard reboot.
Finally, I called it quits on all the tweaking or twiddling. Paid 10% or so return penalty to acendtech and bought myself a mid-2010 Mac for under a gran. It has been 6 months now and I can finally focus on using the Mac then worrying about the fixes.