1/2 no, 7 handed.
Main V1 in this hand seems decent, at least relative to other players. Hero has $425 and V covers.
V2 Limper is on a losing streak and generally typical regfish. V3 in blinds is loose passive, sometimes gambly. Stacks for these 2 are $150ish.

V2 limps in early. V1 limps CO, hero raises K Q on the button to $12. V3 (bb), V2 (EP limper) and v1 (co) call.

Flop (4 players, $43) KT7
Check to hero, bets $30, only V1 calls.

Could be KT, T7s, 77 or a draw like QJ, J9, 98. Maybe AJ/AQ or AK but I think he would've raised pre. Also possible KJ.

Turn (hu, $102) 4
V1 checks, hero ?

Normally against smaller stacks I bet and commit but we have $375ish left to play. Now, this is a total brick and I can probably fold to a c/r but a lot of rivers will complete a straight.

This is a super easy bet fold spot.

Fair enough...how much do you bet? Part of the dilemma is a psb creates a $300 pot if called, and a smaller bet provides nice implied odds

I would go for a bet here and check back a lot of rivers vs checking here and betting river. I think 70-80 is good size here and fold to XR.

Bet again. I'd go $65 - $75. Make him pay for his draws and maybe he'll call w/ KJ or K9. If he has you beat, he will probably let you know.

I would bet 65, so if we get raised we can still fold and we get as much value now in case we have to check back the river.

Yeah I think 65-75 is good.

I like it so far. Definitely betting that turn.

V called a 3/4 pot flop c-bet, so he likes his hand. I wouldn't be too concerned about 2P+ here. Seems like most V's are going to get antsy with 2P+ and check-raise if there's even a whiff of a draw out there, and QJ, J9, and 89 all seem like hands he'd be worried about you having.

Probably bet pot or a little over pot here. Usually I wouldn't go quite that polar, but there's $375 stack depth remaining going to the turn. I don't want to bet $75 on turn, and have the pot be $250 on the river, with $300 back. It'll suck if he decides to flat with a draw and donk-jams when he makes it, or shut down and check-fold when he doesn't.

So, if he's called a 3/4 pot bet on flop with a draw, I'd think he might call a full pot bet on the turn. If he's called with worse KX, he'll probably call a pot-sized bet, too. If he was slow-playing 2P+, we should hear from him now.

If you do bet pot or over-pot, we gotta be really careful going too thin for value on the river. I'm checking back every card that completes a straight, and probably most bricks, too. Even if you bet less than pot, as others are suggesting, this hand doesn't seem strong enough to get three streets of value, which is part of why I'd go bigger on the turn.