[jb9]

Hand 1 I bet the pot on the flop. If I didn't do that, I would have raised SB's turn bet (to 80-100). If SB bet big on the river, I'd consider folding.

Hand 2 I probably bet the pot on the turn -- I'd be worried if I got raised. As you played it, I'd have trouble folding on the river although it does look like button wants to be called.

Hand 3 I might try to steal on the turn (either he has an Ace, flush draw, or I'm taking the pot). I'm not sure about the river. If he has an Ace, he doesn't have the flush draw, so he should have bet on the flop or turn. He may be bluffing thinking you would have bet by now if you had anything. A read on UTG+1 would help.