Why check OTT? The 7s should be better for your oppenent's range, which is actually a reason for mixing in x/r with your nutted hands to induce some bluffs or thin value bets you beat, but on micros people tende to be too passive. This is why I would go for 3 streets of value with bet/bet/bet hoping villain finds a calldown w/ Kx.

As you fold out the very weak hands OTF already, I'd go with 2/3-ish pot to extract value from 99-QQ, some 8x and all Kx. And then I would 2/3-3/4 pot on almost any river, giving him the hero call spot w/ JJ for example.

As played, I like the x/r instead of x/c because it builds a pot. BUT your sizing is WAY to low. As you could see, villain does not care about your sizing, he either continues or folds his hand. Therefore you wanna x/shove most likely. With x/shove you get Fold Equity in the spots you are bluffing (i guess you do not bluff in this spot but ideally you should always have a possible bluff) and max Value from hero calls, which otherwise would scare fold OTF if an Ace or a spade hits.

don't check/raise turn, just bet again (large) and ship river.