OP, most people don't use much rear brake at all. You are coming across as someone that is a beginner, just out testing peoples bikes. I mean, after all, you couldn't bump start a bike. And now, you are crying about a rear brake, and bitching about someone's valves sounding out of adjustment, when I don't think you really know.
Anyway, maybe you should just buy a new bike, so you'll have a warranty. When you mentioned in the other thread about the high season and prices, you let the cat out of the bag.
As for fork seals and wheelies, the'll only blow if they weren't right to begin with, either old, or damaged surfaces or hard seals, or dirt underneath them. How do you explain those supercross guys getting 45 feet of air?
Oh, and I do keep my rear foot on the brake when I'm hanging long wheelies, but I never use it just riding around. To blow off a bike because the rear brake isn't set up in beginner mode, you know, those guys that don't use a front brake, shows your lack of experience.