Hand 1: I think you played it well, obviously this depends on your image and who you're playing against. It's a little better if the board is more like K876 but whatever. Also the turn minraise means you're crushed 95% of the time.

Hand 2: again, i think this is good. If he had anything like a 9 or better he most likely would have bet the turn.

Hand 3: bet river like 7.50 for value