Big river bet with two pair

Pretty bad call preflop, it`s a squeeze or fold situation.

Yes, if you want to be in the pot, you have to squeeze here.
River is a fold. Even turn is somewhat on the border.

Even flop is thin. What is SB calling with preflop and potting with vs two on the flop?

It is not horrible to just call preflop (if you feel uncomfortable squeezing), but then you have to remember that it is pretty much a limped multiway pot, and any serious firework means strong ranges where TPWK = useless.

KTo feels too strong to fold and too strong to bluff-squeeze. When BU is halfstacked it seems fairly unlikely we can isolate SB effectively with a squeeze either.
-> I agree with your preflop call.

Flop: disregarding his range this is my 3rd best made hand 55>KJ>KT. If I folded this I would feel like I was folding too much, although you can easily argue against this point by saying BU will defend a good amount of the time 'for you' so you can fold if you think you are behind.

Turn: I note his smaller sizing. Could mean a lot but won't go into it. Anyway, The hand doesn't feel amazing (though neither does KJ). Seeing as the board is more drawy now though perhaps it is time to switch away from having a calling range and just have a raising range and a folding range.

I'll leave you to guess my value raising range but this might be a hand to put in my bluff raise range. (Please note - on NL2 I'm sure players don't like folding, please do feel free to disregard any advice on bluffing that you may hear)

I like squeezing more, but as DaPhunk said, we probably won't get much folds from this BTN, so calling migh be fine. As played, I think that check/calling the flop is marginal, but probably not terrible. I would check/fold the turn then. Bluff raising the turn sounds interesting, though. but there are probably just two hands, AK and KJ we migh hope for folds from and I doubt the players at this limit are capable of folding those, especially AK.