Preflop would def raise you don't want to give the BB the correct price to get in the hand with any two cards. And you want to charge UTG Ax holdings.

Would make it something like 8-9 BB and call it off if UTG shoves.

As played I think the fold is to tight but not a very big mistake as the BB can easily have a 5 and if he is on a draw he still can beat you on the next street and then there is the UTG player to consider also who is willing to cold call in the middle with a player left to act.

Hi, MrSoloIDolo

1- I would 3bet pre flop 3.5/4x and call a shove, I think if you want to mix a flat with JJ you have to be in the BB but even then I would 3bet get in a big portion of the time. (UTG only as around 40bb)

2- OTF: I don't really get in that spot since i'm 100% 3betting this spot with JJ, but you will never have a better hand than JJ beside maybe A5s,44,55. BB has range advantage in this spot so its not that uncommon to see on donk from (REG/Fish) but he is going to lead a big part of his range (5x,4x,22,33,straight draws) you are still doing good against this range. UTG is going to call a lot of Ax BDF or even just A high some lower pairs 22,TT that you still beat. So I would never fold this flop not to say its impossible to fold on later street.

If you want to take tournaments more seriously I would consider using Icmizer this helped me a lot in these type of situation pre flop where you feel lost.