At a glance,

1) Fold it, 4 people in the pot, the fourth of which was priced in and that board is at least in the 2 pair, set, straight or combo draw range, all of which are unfavorable.

2) Either push or call and decide whether or not to push the turn, if he flat called with 4/6 and hit the nuts, so be it, but it feels like he's protecting a Flush/Straight draw or at worst has a monster draw. I could see some one with KQ there, and I doubt some one would re-raise with a set in that position when he could get 2 more street of value out of it. If he's clever, he's just checking for the AK CBet, in which case he's giving up after a call.

3) Check/Fold, 2 flat calls is well within AX range.

4) Calling there is awful, either push it or get off of it. At a guess MP1 is betting with a PP that missed and the BB has a Jack. If you let the Queen or King hit the board, you're forced to fold any way, so make a decision now.

5) Calling there is awful, he either has you dominated or he's 4Beting AK in position. Gamble or go home, but don't let him have position and the initiative with AK, because you're either go to risk more chips after the flop or forfeit the hand.

6) Re-raise the flop.

7) Bet the turn.

8) Did you get slow played by Aces, a Set, BDFDed or Wheeled? You have to bet the turn there just to price out the drawing hands and sniff out the Aces or the Set.