Thanks guys. RE: the turn bet, I figure he's calling with a worse Ace a good portion of the time, and I want to discourage any free cards to any draws out there.

I called and villian turned over QsTs for the straight. With both straight and flush draws, his plays make sense I guess. There was enough in the pot that I felt it was worth the call, as Ace-lowerpair shows up here, as do busted draws and even junk from time to time.