Hand 1: If this was HU I'd re-raise flop. But in a 3 way you are getting called by either a flush draw or a queen. What is your plan then on turn? Also, look at MP's PF line -- small raise, then called your bet. This person looks more like a calling station than someone who is willing to lay down a hand. Pick a better spot and value bet them to death.

Hand 2 - I'd probably bet more like $2, I like your turn check and fold. This flop is much easier to play in position. Both draws were completed on the turn. Much of villain's calling & non-raising range pf now has completed a draw or has 2p. Just draw to the free spade -- a smart villain may raise your bet here, and you can get the bet back easily if the flush hits the river.

hand 3- pop it to $6 and watch them fold pf. JJ in a 3 way pot sucks. Checking flop, you are toast -- turn is a fold. Flop bet sucks too because we showed no strength pf and with of all the draws out there, even if they don't have an ace, at least 1 player is calling and we have no idea where we are at, and turn or river is highly likely to bring another overcard or draw completion. If you were gonna be HU I can see the call, but with 2 ppl going in I 3bet to at least go HU. Honestly with JJ I am frequently happy to just take downt he pot PF, almost 9bb is a good winrate for JJ anyway. Going into a 3 way non 3bet pot with JJ is basically looking for a set or to get the luckflop of rainbow uncards... so 3bet here.