[dave6]

What's the buyin?

Fold preflop.

As played flop is fine since he bet like 1/6 of the pot. Mid PPs seem to make bets like that a lot, and you have 5 outs to beat Ax. If he fires a bigger bet on the turn, and you don't improve, you'll need to fold. I think just folding the flop is also ok since there's 2 more betting rounds and you don't want to end up losing 3 bets to A2 or whatever he has.

Definitely bet the turn. As you saw, giving the free card is a disaster here.

River is a tough decision, but if you had bet the turn you might not have had to make it.