KK, do I have a value bet OTR?

I don't think many pocket pairs would call a third barrel. I don't know if you can bet for value but maybe we can call this a block bet? If villain calls with a pocket pair OTT maybe he sees an opportunity to bluff when flush completes and you check. I still wouldn't like check calling so I think our best options are bet fold and check fold.

I would have made a bad check and call a moderate river bet after hoping for a free showdown.....Then again I made a bad turn fold with KK today v 2 opponents grrr.....

Villain seems not to be maniac, I would c/f OTR. The thing is, if he bets OTR, he bets always with better hands. In this case: Jx, FH. Rarely you will see guys do doing it as a bluff. Another option would be bet F, c T, b R. However as the villain might be drawing, it´s better b F, b T and c/f R imo.

I prefer bet-fold over check-call. This is one of the hardest situations to evaluate, and very common. Very opponent and stack size dependent. Check-fold and even (rarely) bet-call may be viable options too. But don't fall into the trap thinking "if I do this and that villain will always..." They don't. Some even bluff with made decent hands.

Assuming it was a bet/fold OTR I agree with your line. IMO Jx or FD would raise that river (Set or good Jx would raise before probably) so extract value for whatever hand he can have

Opponent looks like a hobby player. Dont think it is a clear value bet. But if he calls with poket there, then you will get a note that you can value bet him thin.