hand 1 bet 10-15 on the river and fold to a raise.
hand 2 isnt great imo. If sooted then i can understand wanting to limp preflop, but id prefer to do it after at least one limper.
Hand 3. I never believe this but i prob fold because it just seems too fast. Fwiw, i might c/r hard on thsi flop because it seems like we missed. The only hand our opponent is likely to have is 66 imo, which is why id add the straight seems unlikely. Does he really think youll call that bet with your expected range? (and i dont think thats overthinking for 50nl)