Checking for sure on this river. I'm probably looking to check call this river. Checking is cool because he can certainly have a lot of missed of flush draws as well, but not have a pair, so he might very well bluff this river card for this reason: 

He has possibly has no show down value and we hav basically repped QJs, KJs, maybe the offsuit combos of these two hands, KK, QQ, and then we could possibly have a missed flush draw that didn't actually make top pair in this case.

I'd expect most people to raise the turn if the T improved him. I mean, if he is slowplaying a set he will want to charge you for the river, if he had JT you'd think he will want to build a big pot now and again, avoid ugly spots on the many bad river cards.

If he overbets the river, make the choice of how often he's bluffing here. (Look up his W$SD stat is a good one for figuring this out)

I suppose you can make an exploitable bet on the Turn (such as you did) to allow yourself to draw at a reasonable price and not allow him to decide the betsize on the turn. Given that he's a fish, I don't assume that he'll pick up on you betsizing tells. But I also don't see you having a lot of fold equity on the turn since his range is going to be full of pair+draw type of hands which are never folding. River I would c/f to be honest; I think that he'll have many SD value hands (Jx, Tx) which he'll never turn into a bluff and some 2 pair type of hands which beat you. I'm not sure whether he'll call you light enough to justify a value bet (QJ and KJ might call, but that's about it); I think the ace gives you SD value and not much more, so I'll check here always.