First I have no idea what I'm calling and squeezing here. The last time I played consistently you'd 3bet wider here because the first caller was dead money but now people seem to have worked out that they're allowed to call squeezes so I think I'm meant to be squeezing less? SB is probably only a part-time student of the game so maybe my range should be warped a lot but assuming a standard SB would a 3bet range of something like AA, KK, 6 AKo, 12 AJo (or is this an overcall?), 12 Ax suited, 12 SCs be reasonable?

And then if that's my sq range I guess my overcall range is QQ-22, all the suited broadways and some good suited aces, AQo (does this play so badly 3-way that I just sq it as like, a sort of bluff?), and some of the better SCs, maybe down to 87s?

Here I just don't know how to play my range. It's really hard for me to conceptualize how important different things like forcing HJ to face a bet with a player still behind him and avoiding giving two people a free card are. It seems intuitively like a good spot to be betting most of the hands I am invested in playing but to not always be weak after a check. What if I bet something like:

TP+ except some KXd, AdXd except AQ and AJ, QJ QT JT of diamonds and spades, AsXs, 999/444.

That leaves me not completely gutted on the turn and able to defend vs a bet a little. This is another thing I have a hard time conceptualizing, but it seems like with three players our checking ranges need to be able to defend far less often than with two players since people can't bet anywhere near as much just to take the pot down vs twice as many potential calls, so we're more incentivized to put more strong hands in our betting range.

Again, I'm ignoring the fact that SB is probably playing with money from his day job here so far but now that we've gotten through all that other stuff the fact that SB is likely aquatic does warp my strategy a lot more towards a x/r right? HJ will want to valuebet wider than otherwise and SB gets to act in ways perhaps comparable to those of a grass-eating quadruped before the action gets to me again.

Money in the bank.