Playing $1/$3 NL 9-handed at the casino. The table has a kind of loose-passive/sh*treg dynamic: people are never 3betting without premiums like {QQ+, AK} and some players will even flat with those hands, there is a lot of limping going on with junk hands like T8o, people are getting a little too sticky postflop as well as not showing enough aggression with TP hands, but the only aggro thing going on is open raises: people are happy to raise to $16 pre with a hand like QJo in the Hijack.

OTTH:
We're $300 deep and dealt AJss in the BB. Everyone covers.
UTG+ 1 raises to $13
3 callers
We 3bet squeeze to $65
3 players call
1 player folds

Flop ($260, 4ways) is Jc 8s 7c

We jam $235

Is this all completely standard?

Yeah, except if I'm going to squeeze, I'd size it a little bigger.

I'm kind of skeptical to 3b an EP opener though unless they are raising a lot or have a sizing tell. However, once you squeeze and get this flop with this SPR, there's no getting away.

Looks fine to me aslong as +1 isn't opening too tight

The problem with raising bigger is:
1) I'll rarely get called by worse if I make it $100 pre, since the absolute value of money will start kicking in, and:
2) I'm now in a really awkward spot if someone jams $300, since I'm now getting better than 2:1 odds on a call.

I felt that $65 was a sufficiently large sizing to "protect" my hand from low pocket pairs (which aren't getting the odds to set mine), suited connectors (which are getting a horrible price to see a flop) and weak cards like Q9o which would otherwise have the chance to realise their equity against me. But I am open to opinions on this.

I also think that UTG+1's range is slightly more weighted towards medium strength hands like ATo, KJo and 87s, due to his sizing. I think he'll sometimes raise bigger like $15+ with premium hands like {TT+, AQ+}

3betting medium strenght hands oop vs 4 loose passives with this stacksize is high variance and might be borderline bad imo. I'd just flat AJs and 3bet a more polarized range.

1) we want some fold equity, we dont have a premium. folding out 77 or KQ is a win imo.
2) if they arent calling with worse, they arent shoving worse either and we are not getting correct odds to call a shove.

65 is not the right sizing for a standard raise, in this spot, with $50 out there, a standard 3! Is 80+, often $100 or more, realistically a smaller size like the one chosen will almost always get at least 1 caller (and villains may prefer to jam)

Given how shallow the stacks and that hero has no particular reason to think utg+1 is out of line I would wait for a different spot to squeeze
Even if it is marginally +ev, it is going to be a very high-variance spot

As played ship the flop

$65 seems fine if you are going to 3 bet, I don't like it in these conditions tho. As for flop, you have no choice.