hand 1: i think check on turn is fine, it certianly would seem he had a flush draw after he just calls flop. i would call turn maybe bet 1/3 on river and fold to a raise.
hand 2: fold turn
hand 3: i like it alot. any hand that would call this allin would usually raise the flop, and if they have KQ or are attached to KJ then at least you have outs.