[Nikla]

Hand 1 is the kind of hand you need to call occasionally but fold the vast majority of the time. I dont think the turn 3-bet is an absolute given either.

Hand 2 is well played. By raising turn, considering that the board just paired you might make him fold an 8 or a 5 which you naturally dont want. By waiting until river chances are he'll be making a "curiousity call" more often with his pair. On the other hand if river is an ace or paint it might freeze him into check-calling, and if he was on a draw and river is real ugly like a blank ace or king he might whiff and check fold.. If its an ugly card for you,it might freeze you up, like the 5h or an 8. You also might lose a bet when river comes down a heart and he check-calls or bet-fold (assuming you raise a heart river). So I guess I agree with gambler that it doesn't really matter if you raise turn or river as long as you do both.

You shouldn't discount the possibility that he has a 3 either. I bet out like this with trips often. Naturally if you get 3-bet on turn you should be much more inclined to call down than if you waited until river and got 3-bet there.
-Nikla