Hand 1: Fold pre-flop. Post-flop I'd neither fold nor push.
Hand 2: I'm inclined to bet here if you're comfortable dealing with a raise.
Hand 3: It's fine.
Hand 4: Fold pre-flop. Given how shallow the money is, I would just felt this if I see a flop.
Hand 5: If he sucks then play for stacks.
Hand 6: Turn bet would be a reasonable play. River bet is pretty terrible.