[infinity235]

Hand 1: Raise the river for value, please. If MP2 has QQ he is an idiot for not raising preflop. Most of the time, you have the best hand here. 34 is very unlikely given turn action.

Hand 2:
Flop: Small pot, middle pair + one-card gutshot to the nuts. Raise or fold. Do NOT call.
Turn: You HAVE to bet here, but when check-raised (lol wtf??? bb bets the flop then c/r the turn?!?!?), you can safely fold. You are behind here most of the time and drawing to at most 6 outs (I'd discount them to 4-5 outs because you might split if you hit your straight). You get 1:4 odds. Fold.
River: Raise or fold b/c of SB behind you. You do not want overcallers (with weak aces) here. I tend to fold b/c of BB's strength, you are not good 1 in 10 times against both players, and not good 1 in 5 (maybe even less if BB 3-bets) times against BB alone.

Hand 3:
Flop: Standard
Turn: Raise here. If you are afraid of the nine, play weak-tight poker and let go. Flush draws aint gonna fold here, but your target is weak draws... If BB has a nine, so be it. But you have aces up and are good against any two pair here (even though BB's donkbet is a little bit scary). If BB 3-bets here you can be sure that you are behind and call. By calling, you gained no information at all.
River: UTG+2's river raise indicated that he hit the king and has kings up (not kings full, where he would've raised the turn), and BB's 3-bet... well... you get 1:9 odds here... I don't know.