For some reason I can't post the hand history so I'll just explain the hand: UTG has 20BBs and raises to 2.5BBs, I'm in the SB with AJo.
I have only 4 hands of villain, so no reads. I decided to flat (first mistake?). The BB calls as well. The flop comes 8h9cJh. I check, BB bets 3.6BBs, UTG folds, I shove.
We were 45 left, the tournament already took 7 hours and I was tired, and I think I played this hand pretty bad :(

1) Is flatting pre an option? Looking back I think I would either shove pre (if I had reads on villain that he does play a wide range in this spot), or just fold, which I think would be the correct play in this particular spot.
2) As played, is check-raising on the flop ok here?

Sorry if this is a standard spot and I just suck :D