Hand 1 - I don't mind c/c here on the river sometimes, but probably lead pretty often. Depends how bluffy he is, but I'd imagine he'd call with more marginal hands than he'd bet with.

Hand 2 - Brutal river card, you just can't raise this. K river is just so bad, I'd be inclined to flat a lead here even if it wasn't four to straight.

Hand 3 - I think I'd check this river, since so many insiders/FD's didn't get there, and he's never that strong here. Betting can never be bad though.