IMHO, you are missing value by not raising an calling if bet back to you on the river.

Casting my mind back to this kind of level (I guess this is pretty much like Stars .05/.1), the check call on the flop then going nuts on the turn smacks to me of a slightly thinnking, pretty agro player at this level trying to get tricky.

The range of hands that villain has is pretty large, if we cross our fingers and hope that he is bright enough to 3-bet AK preflop (maybe a 50/50 shot of someone doing this at this level), this leaves us afraid of three hands AQ, a slowplayed KK and 55 (again, at this level I would guess at a 50/50 chance he would have dropped this on the very threatening flop).

This leaves us with a vast range of hands that we beat - Ax, Axs QQ-22, if he rivers you with A9 / 99, shug shoulders, try hard not to tell him what a suckout laying fish he is and try and play with him often.

This range of possible holdings is too big to miss value on the river IMHO.