He's fine in AAA. Don't demote him.
He can definitely play in the majors, but I'd wait until he's more fully baked in the minors.
I'd leave him in AAA this season, then call him up 20 games into next year. His Durability should jump this offseason, hopefully to 70+ or so. Also his range should jump this off-season so his 2b defense will go from damaging, to hopefully respectable by next season
Watch his playing time (I'd platoon him). When guys get too far below 100%, the become prone for injuries. With his Health, that is a serious issue.