Don't see any sense of 3betting pre against lag reg. call pre and play postflop poker.

Could imagine he raise/folds hands like TT,JJ (would be spewy to be honest) for protection against hitting your probably 6outer. He definetly could hold 99/88 but unlikely as u said.

I would fold here, because we have almost no BD-Equity and we often have something 3 outs and 0% equity.

Im also in favor of just flatting pre when we don't have some sollid reads. Its still an utg open, we close the action, no reason to 3bet at this point imo.

I dont like your flop cebt size after preflop 3bet , a little small, for this board, hero should bet strong vs a lag Villain. I will bet $12-14 for this flop always 3/4 pot, 99+ in our 3bet range.

Since you are 3betting a wide range Vs UTG it is kind of difficult to say who those board favours, but it is likely better for villain. As he still has all his slow-play overpairs, pocket pairs, 89s, 9Ts, JTs. AQ+.  

Given what i can only guess your pre flop range is here, i would probably prefer to check call the flop for these reasons. And have to fold alot of turns.

As i seem to say alot, you just shouldn't be in the spot in the first place, you are making your life more complicated than it needs to be, and really not gaining enough value with this section of your range to warrant 3betting preflop. + if you are 3betting this, your flatting range Vs UTG when in the BB is going to be pretty damn weak, and very unbalanced.

I also do not like the 3bet preflop. It seems better to call I think. However as played I think the cbet is also a mistake. Presumably AJ is towards the bottom of your 3betting range preflop(?) and given that you have no real backdoors to speak of I can't see the bet showing a profit unless this LAG is overfolding this board which seems unlikely to me. Cbetting AJs with a backdoor fd is fine I think but this combo I would just checkfold on a pretty unfavourable flop.