a) Because David, like the majority of other OVW/HWA/developmental talent, wasn't up for the draft. (Lesnar, Mark Henry, and Rico are presumably being bumped up to the big leagues, but they're exceptions.)
b) Dunno. I think that'd be a pretty amusing angle, but then I'm a Test mark. Of course, just because Test shows up at Raw doesn't mean Flair has to book him, or even let him in the building, but he could always do a run-in. Maybe Vince will send him over to get the Hardcore title back from Raven.
I posted this on another site I frequent, might as well post it here: When Batista was traded to Smackdown last year, he wrestled and beat Orton on his “last” Raw episode. Was Orton the champion at this time?