1st hand AA: Bet the flop a lot more. With such a small bet on the flop you can have no idea where he is at. He could even have Q9, which would have been folded had you bet more.

2nd hand QQ: If you were planning on betting the turn if another undercard to your hand came, then why not re-raise the flop. If he comes back over the top then you can know you are beat and can fold easily. I think the better play would be to check-call the turn and river. With all the min.-raising that guy is doing you would have been able to see his cards for cheap.

3rd hand A8: Well played. I love people who think that just because you check when the flush card hits you can't possibly have the flush. I'm assuming you had a read that this guy was a bit of a donk, as better players would be able to fold to that big of a raise on the river.