Can't help you with any of the other but here is a tip that you may already know. Just in case you don't, here it is.
Most manufactures do not warranty a used bow. Basically to get the full warranty you would have to by one new from a dealer, does not matter what the seller says about warranty cards. The good thing though is that if you ever have problems with something like limbs, and you buy new ones, those will be covered. If in doubt, call the manufacture first to find out about warranties on used bows.
With all that in mind, I have bought used bows and have been pretty lucky so far.