Hand 2, the river is very intereting.

Bet/folding loses merit because we can get bluffed off this pot. Check/Calling loses value on the hands he would call with but will check behind and you are going to get bet at by almost every flush and quite a large variety of other hands.

I think the ranges that both of these rivers are against are very large and I think that check/calling and bet/folding probably have the same EV. Bet/calling I really don't know about because I am not sure how often he will bluff/raise this.

True