You have to put into consideration that a person flatting in the blinds vs an UTG open would probably be a lot tighter than one flatting vs a late position steal. I don't think villain would have many 8x hands nor J9/QT hands in his range here. The range that yAAwn gave above is already wider than what I think villain would be flatting w/ in this position. We could give him a few combos of 8x hands, but it would be much less than you give a relative unknown credit for.

I think I'd raise the flop for value and as played, I would be betting the river something like 1/4-1/2 pot for value as well.