Pre I flat because bttn and bb aren't playing 100bb so probably weaker players.

Otherwise I woudve 3b I guess, although flatting would be still fine imo.

Villain plays 27 27 after 22 hands, no further info.

I expect villain to cb this flop a lot, the flop is pretty dry. I decided to float and call when the turn comes a/j and fold on other cards. Probably bluff when villain x the turn.

Now he checks the turn and I wonder if betting is OK here? Can we expect villain to fold 22/44/66/88/99/tt/jj?

I guess he folds 22/44 and x/c 66/88/99/tt/jj and fold ak and fold other hands like kj/aj/at maybe something like 89 or ax if he opens those. When I see that range, there aren't a lot of better hands that fold when I bet so is checking better? Or should my plan to bet turn and a lot of rivers to fold the rest of his range?

On the river I bet small to fold out ak/99/88/66/44/22. Maybe he puts me on at/tt, maybe still kq.