I think checking flop is fine. A lot of hands that have you crushed after they flat called your 3bet

Turn bet is fine

When river bricks, I think check calling (depending on villains sizing) is best. If it was vs. 1 opponent, I might bet. There's missed draws that might bluff and we're only really getting value from KQ and AK (presuming they villain doesn't 4bet GII PF)

Well played imo

I like the flop check multiway.

Turn bet for value is standard.

If both players are fish then I would still bet the river. Their mindset can be that you don't have Kx because you never bet the flop and because calling is likely to lead to a showdown you can still get called by hands such as KQ AJ QQ. 30bb would be fine I reckon.