I think the bet after the turn is suspicious because the other two guys called the big raise after the flop. Checking after the turn would have been more conservative since you also have a nut flush draw.

In the final situation, I am a little bit closer to folding because you have been betting crazy nonstop preflop, after the flop and the turn. The guy possible thinks (knows) you have AQ or AK something and he wants you to call. Folding is not too bad in this situation because you will still have some chips to beat this guy later.

Also your check after the river is an indication of a weakness unless you checkraise the guy but you dont have enough chips to do so unless you want to commit yourself all in. I would have folded this hand.