hand one:
fine, except the river. What's with that minimum bet? Unless you're sure he's going to raise you. If he's holding shaky holdings, he'll just call.

Hand two:
should have folded that one at the flop. all the 6's beat you and the aces beat you, but since you hit the turn, we'll analyze post that.
Your play is fine there. What do you have to be afraid of? quad 6's and a straight flush. Let them catch the flush perhaps and then go.