Hand 1: I'd check turn behind here, don't know if I'd call a river donk (small one maybe).

Hand 2: I think I'd let it go too (without a lead I mean, def. now after a bet and call). With the King of Spades in our hand I would certainly lead, but not now. With a lead I would want to take it down right there and shut down to further action. And because this flop hits their 3b calling range I would expect action and hence think a c-bet is spewy here. QQ, AQ, AK with K of spades, maybe 55 for the overcaller are all hands in their range, so clear fold after given action I think.

Hand 3: I wouldn't bother. Opps have silly stacks and probably call you down with a pretty wide range because they're bad