Hand 1: Ship it. Your plan postflop is to bet until all of the money is in.

Hand 2: Bad fold. Put him on a range. There aren't very many straights in it. You should just get it in on the turn, though.

Hand 3: The river is an easy call. Put him on a range! Your flop bet should be bigger. To give you an idea of why, consider the odds you're giving him to call.