I am new here, but here it goes.

On the flop: Given the pot size and the UTG's bet I would raise to find out where I was at. Two things could happen. One is that the UTG could re-raise and protect some of my outs by getting MP1 to fold (or unprofitably call) a gut shot, weaker jack , or another ace like AQ or Axs that has a backdoor draw. The even better result would be if MP1 has a weaker king that he decides to fold.(unlikely). I would not be counting on MP1 having Q,10 and a call from a reraise would let me know that. If the pot were smaller I might dump it. But calling is the worst to me because you have no idea where you are and end up putting yourself into the position you had on the turn of having no new info about the hand. If UTG does have a king even with a poor kicker he would come out and bet, and you could be confident he has a King. If he checks on the turn, you can see if you can pick up the pot and/or put yourself in position for a free showdown,or take a free card.and if By checking the turn you could be in a position to pick up an ace or even make a call which you did in the end. This way you would have gone till the end with the same investment or less with the added chance of picking the pot up and gaining a BB on the river with a third jack.

The turn is tricky because it would be hard to raise and represent a 2, and you had no information about where you stood. UTG could have been making a continuation.

the river was the sketchy part, I know the pot is big but really what could you beat. The King did not scare him. What do you think he thought you could have, beside a Jack or an unlikly QQ or AA Q,10s. All that he could beat.