[william288]

I think:
1) sb plays well until river. most likely he has k with weak kick. His turn donkey is to prevent free card for a draw. he should fold river since both bb/co have a.
2) bb also plays ok. his flop call/reraise most like means he has a-high flush draw.
3) co is relative bad. if he has aq or aj or qq, etc, he should fold turn. his river cold call 2bet means a helps him. if bb/sb are good, co should call instead of 3bet. because 3bet achieves nothing, sb will fold his k with weak kick. if bb has a with weak kick, he also should fold to river 3bet. basically cold call 2 bet can get more.