Hand 1 - I like the bluff, especially after his sizing. I wouldn't have even minded it on a non-heart river.

Hand 2 - The flop is SO dry. I would bet $10-12 on flop, and size turn for a bit less than pot on river.

Hand 3 - Easy b/c. If I'm flatting pre I usually just c/c down and protect my c/c range. I feel like I'm not really c/r bluffing utg openers cbets all that much from the blinds, so I don't need to necessarily have AK in my c/r range.

Hand 4 - His flop raise is high. I would probably jam river. Feel like a fishy type might convince themselves to c/c a smaller bet on river with like KQ or something.