AK OOP 3BP

There is no way you should fold here against a light 3better. You have to be right less than 30% of the time to make this call, and there's lots of combinations that make sense that you're beating, like A2s, A3s, A4s, 67s, 89s, T9s, JTs, 55, 44, 77, and of course he could have AK for a chop.

I think my main concern is yes we beat those hands but I don't think he will bet a lot of his Ax on the river as it would be very thin?

Yes, I agree that it makes no sense to value bet a weak ace on the River. But I didn't think he'd value bet them; I think he could bluff them. After you call the Turn, it's very hard to give you something worse than a pair of Aces, and any Ace you can have beats him so his little A3s has almost no showdown value. The Q is a reasonable card for him to bet to get you off a stronger Ace.

This is true in isolation, but most players also don't 3bet bluff, and you specified that this person does. If you're 3betting a hand like A3s, then getting stronger Aces to fold has to be part of the game plan. If you're not willing to do that, you should probably bluff other hands instead, like suited connectors. (Which is actually what I do, but 3betting the low suited Aces is GTO approved.)

You need to be 4 betting AKs pre, especially if villain 3 bets light, especially with your small initial raise. You want to start with a bloated pot that makes it easy to get stacks in when you hit it . AKs is a slam dunk 4 bet

As played , I am calling, you haven’t really shown strength throughout any streets , I bet villain can do this with even worse than Ax . You will be good enough to call a half pot bet