[Austiger]

Calling or folding PF is fine, based on reads, style of play and the way the match is going. There are lots of ways to play HU and neither calling nor folding is wrong per se.

River is an easy fold IMO. What do you think he thinks you have after calling PF and flop and leading the river? Seems like a really bad place for him to bluff. I think the turn hit him in the face. JJ maybe?

I think I like a check on the river. I don't think he's paying you off without the ace since you played it just like you have one, and he will often view the river as a bluffing spot (if you check, not if you bet.) If he does happen to have KK/QQ, then he'll probably value bet the river anyway.