FYI, my car has always "pulled" ever so slightly since new, when I would reve it up, while still in gear, with clutch fully depressed. I have had 2 clutches in the car, oem and oem replacement once the first one wore out. Don't know that its typical for vipers, but was never really a problem, as it doesnt move the car but an inch or two, and a quick tap of the brake would stop it if I was worried. Or just simple take it out of gear when i pipe someone while sitting at a light ;-)
Now your other isssue, I would rather see the parts in hand then to try to make a guestimate as to what was wrong. Maybe you should keep the alumn flywheel, and just change pressure plate and clutch disk and throw out bearing. If only you were in NC, I would be more then willing to give you a hand, clutch replacement is a viper is a complete BREEZE, if you have a car lift, and a tranny jack (for which I have both).
Jon