So should I root now having FRG01B... or wait for the FRG22 update and root then?
If you're going to root, root now. There's no benefit to waiting except there might be another rooting app on the Market. DMUpdater should be out soon, if the Devs can figure out how to not leak an exploit to the hacking world that would put the entire Android community at risk. Easy Root will do it, but it doesn't do the greatest job of rooting -- though that could be (mostly) user error. The rescue squad is going bald helping out bad roots, and I've lost a few myself with a couple of people.
But, really, once you're rooted you can install everything you want, so there's no reason to wait if you want to do it.
Does Verizon intentionally leak these releases to get some beta testing in before the real release?
Yeah, we've wondered about that. The answer is we don't know. Of course, if a company were leaking things it'd be Motorola, not Verizon. Most likely it's an employee and the company might be turning a blind eye, thinking "free beta testing". I stress the might because I can see people losing their jobs over the leaks.
If I were to root now, I wouldn't be able to download Flash Player off the market correct? Don't you have to have FRG22 first to download flash off the market? This is why I'm hesitating to root now or later.