In response to the hands above.

hand 1 - WA/WB situation here. Don't raise the flop. All you're doing is shutting out the portion of his range that will keep bluffing weakly at you. Let him.

hand 2 - Good way to rep missed overcards on the flop that hit on the turn. You'll usually get a fold here. If not, you're almost always up against Ax and can fold the river or check behind.

hand 3 - That weak bet from a bad player sure looks like a hand that missed and is trying to steal with a c-bet/block w/ a big spade (or keep players in with the nut flush). It'd be tempting to try and steal it heads up with a flop raise, but you've got 2 players behind you to act. I'd actually fold the flop given your terrible relative position.

hand 4 - This is fine. Most hands you're ahead of on the flop now beat you after the turn. There are only a few hands in his range you're ahead of now. Not worth putting any more money in.

hand 5 - You're not ahead of much here. I think the best you can expect is a split pot. If the villian was more aggressive, there are a couple of hands you could be ahead of in his range, but this is a terrible spot to be in against someone with a pfr of <3 and an AF<1.5.