2/5 9-handed table.
UTG1（$1000)~An unkown young guy who just sits down with max buyin and seems a regular.
MP（$1200)~a huge stationy fish who calls down super light.
BT($900)~ semi-tight mid-aged white guy who overplays hands sometimes.He was seen 3bet with 88 in mp and call $350 CRAI on J63 flop.
Hero SB（$850): Solid young TAG with a clean image.Hero AQ.
UTG1 raises $20,MP calls,BT calls,hero calls. Is preflop $125-$150 squeeze better than calling?I'm on the fence in this situation vs ep opener given all these deep stacks.
Flop($80): A J 6 hero checks,UTG1 bets $60,MP calls,BT calls,hero folds,flat or raise? I really hate this spot OOP without knowing where i am.

I like flatting to control the pot and UTG1's range may be very strong. In the live games I've played I doubt people will fold to a raise to 60 unless you have stacked someone and even then it's really difficult to thin the field so I reserve raising to ISO usually for QQ+. And there are times you will run into something like QQ+ and get 4 bet and have to fold preflop. UTG+1 may have AK here or AJ so you may be drawing dead.

Without reads I am flatting the pre flop raise.

I don't want to play a big pot with a possible reg oop without some reads on their play.

As played I would just call flop.

Raising over reps our hand and you can't really rep many strong hands.

You wouldn't flat AA pre, So you can only credibly rep 66 and possibly JJ, AJs.

before I would like to know what the effective stacks are.
I think you could squeeze or call. I would lean toward calling pre with good relative position to the raiser and skilled post flop skills. I also would donk out on the flop to get value and information about the preflop raisers hand and iam assuming he going to have to play honest in a mulitiway flop and get value from the other donks in the pot. I think that is the most optimal play to get value from worse hands because the pfr is going to check the flop with a high frequency if he flops anything less than top pair. Also you are not giving away free cards to beat you the times the flop get checked. I would just bet fold vs deep stacks and bet call off vs short stacks on flop turn and rivers given a small spr.
As for squeezing pre effective stacks would be helpful. I don't think you need to make it huge. I mean your just want the pfr to fold and the donks to call which I think will happen most of the time.

I like the smooth call pre and flatting on the flop. By 3-betting pre, we chase out hands we have dominated and we are out of position with a bloated pot against callers who now have a more solid range (by calling 3-bet).

The flop is not super draw heavy and I think we are still a bit in the dark as to where we are. With 3 others in the hand, AK and AJ are definitely possible (esp from UTG+1, perhaps the others would have raised), as is it very possible you have the best hand. Since we are still in the dark, lets call here, check the turn, and gather more info.

Pre - Vs. an unknown, I think flatting is best.

Flop - C/C. We may be a bit lost, but raising is not the answer imo. Unknown betting 4-way shows strength, at least for the moment.

Turn - C/F if PFR bets strong again.

Flat pre is perfectly fine/standard here. No reason to bloat this pot pre with our hand when we will be OOP on future streets AND it allows for some deception b/c AQdd falls into the stronger end of our flatting range. Check/call flop is my standard here against most regs.

I hate it too. If you call the pot will be 320 on the turn. Another 3/4 pot bet will be 240.

Unless you're prepared to play for stacks I would fold. I wouldn't put 60 into the pot to fold on a later street.

There's no possible way to keep the pot small.

I wouldn't squeeze AQs out of position in a multi-way pot.