#1 I like your line (maybe bet the flop a little harder). Fold to a turn raise though.

#2 I probably call.

#3 Preflop raise is good. Sometimes I call. As played bet the turn and fold to a raise, similar to your line in hand 1. A lot of villains will call your flop bet with an underpair because they believe you are on missed overs. Betting the turn should straighten that out, plus make it a little more sure as to whether he hit a set.