Flatting pre flop is a good idea. It shouldn't be your standard, but it's something you should definitely be doing from time to time.
UTG is a fish and we always want to play against fish. BU's range is pretty weak and includes a bunch of weak aces which you want to keep in the hand. Your hand will be disguised because BU expects you to 3b something like AQ. So it's a great spot to flat AQ OOP IMO.
Villain seems kind of passive, so he might be flatting his FD on the flop, instead of raising them. But I expect him to raise TP/TK or better.
So here are my thoughts: Against an aggressive player, I like c/rAI the turn because his value range for betting the turn is practically inexistent. He's probably raising a J, a flush draw and a set on the flop. So when he does bet, most of it will be bluffs.
However, against a passive player: I'll bet really small on the turn, like $20, because he's only gonna raise us with the flush. We pretty much set the price of our draw. On the river, I'd ship a K, an A, a Q and a
obviously.
I'd ship the K because there are many hands he can still fold, like 88-TT, 7x, 65. There are many J's that he'll still call, but there are a bunch of blockers to his J combos (your A, Q and the K on the board.)