[ike]

Hand 1, if you specifically know the player doesn't run big river bluffs then anything he's raising for value beats you. However, I wouldn't be too surprised to see K-high if you call against many aggressive players, so call.
Hand 2, your hand is basically face up and he's checkraising, I think he has to have 2pair or better. Fold.
Hand 3, when he calls your turn donkbet it looks like he's going to showdown. When he then raises the river I don't see what you're ahead of. Fold.