Hand 1: bet/fold on the turn is what I would have done too. There are many hands that beat yours and while there are many hands we beat, I think most of them call the turn vs. semi-bluff the turn. What suits did you have?
Hand 2: I think I call the turn in heat of the moment. Getting 3:1, need 4:1 I think. Most optimistically we could say something about implied odds if we feel an A/K/
wins your opponents stack on the river and rationalize it. I'm sure some people raise the turn too, figuring only 7x/boats call a shove and that your opponent could bet the turn fairly wide. However, my counter to that would be - we checked back flop multiplay and with no reads our opponent could snap it off with any two pair. Don't think there is much fold. I'd call turn.
Hand 3: bet/fold on flop seems fine. Do you have T
? What was your plan vs. a caller on a variety of turns?
hand 4: Seems fine. I might go smaller on the turn. Opponent is going to have between $150-200ish behind after a turn bet regardless of sizing, pot will be $270ish+ most of the time too. There isn't really much harm in sizing slightly smaller. All in all, either you or him is getting coolered or your opponent is going to make a mistake. Not much too it.