[elindauer]

First fold is straight-forward. In fact, given your river betting range, you can probably fold this unexploitably, meaning that folding to a raise there is probably the default play. Given the scary board and the expectation from villain that you will be calling with an ace quite a lot, I think you should fold more than game theory would suggest, not less. Clear fold.

Hand 2. You probably hold the worst hand in your turn capping range, unless you are capable of capping the turn on a draw (are you? not many are). Given that, from a game theory POV, your fold may be right a fraction of the time.

That said, I think you should call. I see people river 2-pair and think it's the nuts when they are clearly beaten way too often to lay this down. Sure, you can lose to UTG playing a higher set very nicely here, but I think you win more than 1 time in 20.

good luck.
Eric