Hand 1: Why are you calling the turn?--to spike an A? This is a perfect example of "you should just bet if youre going to call". In this case the on the flop you are beating almost this guys entire range and on the turn you are now a hug dog to a Q but the thing is he could have taken his line to the turn with any number of hands besides Qx although his nittyness makes me think its not THAT many. In this case your two options are check/fold or bet/fold to a raise, definitely not check call.

Hand 2: in this hand so far you made a standard raise and then a standard c-bet fine. Now here there is a completed flush and 2 kings. It is perfectly conceivable that you are ahead of his range but what is he betting the turn with?--only things that are beating you!--barring insatnity. So check/fold the turn. If he checks behind then it gets more complicated.