If you overbet your perceived range is : 55, randombluff.

bluffing the turn makes waaayyy more sense than bluffing the river.  Why would he fold 66 now?

VS this on the flop {JJ-22,AQs-ATs,KJs+,QJs,JTs,T9s,98s,87s,AQo-AJo,KJo+} (11% since he may not call 14% CO vs UTG even with a 9% gap enter his VPIP/PFR) we have 28.4%.

And with villain folding to CB so little I would just check flop. He may call all the Ax, FD, J , pp and I just don't want to multi barrel this spot vs a passive player with almost no equity. 

I think this situation is kinda tough on the flop. On one hand, you could represent or have an overpair or AJ or even Ax that is ahead of villain. In fact on the flop, your range is better than villains range probably by far, and he is probably very capable of floating because it really doesn't look like this board hits your range that much.

I just don't know, maybe the solution is to play tighter in EP or, no I don't know.. I think this kinda difficult situation but not that much money involved

I think, by the river, villain knows what you have and it's risky to try to overbet. If you do overbet, then you might have to think about how to not be exploited, it seems like the villain is likely to fold his small PP which is what he has probably 90% of the time, but he may also be capable of calling with them because he may suspect you are trying to steal. And also on mycrostakes, people can play strong hands weird and you never can be sure what someone is holding or how someone is going to play. I think overbet is risky.

"I think, by the river, villain knows what you have ..."

How that? Hero could´ve gone for the x/r on the turn ... and overbetting with our ENTIRE valuerange is the correct play in this spot because it allows us to maximize the amount of bluff combos we can add.