[ProfessorBen]

Hand 1: Preflop is thin, but fine. I like the c/c on the turn. It's terrible if he checks behind with his 6-15 outter. As played, river is fine, but history and opponent dependent. There are still 5 cards that are bluffs for him (A, K, Q, 9, 8), though he should be checking behind most aces.

Hand 2: I bet/fold the turn, but a value check is not bad. As played, fold this river. Very few hands that are calling this flop are behind you at this point. This is a not a bad time to turn-value check, but you don't have to call all rivers. This and a K or a T are the other ones.