Hand 1: You have to bet that flop - your assumption that you are WA/WB is way off (no pun intended). Many players will peel here with any pocket pair, and also hands like k 9, jq, hoping you will check the turn.

Not betting this flop is also the most transparent slow play in the world. If you had j9 would you bet this flop to represent the ace? Of course you would. Even the poorest players are able to see through the ol' raise pre flop check the ace high flop trick. When someone does this to me, they have an ace. Always. Always always. So bet the flop and hope he pays you off with a worse hand, which he often will.

Hand 2: I think the river is a check/ fold here, although it's not a terrble board for a K high call down. I have trouble making it though, I think. The fact is that when he calls the turn and you have just K high, you're probably not good all that often.