I imagine that many slaves were spoiled or pampered by their owners, and according to the social standing of the owner, the slaves would feel they had more leeway in dealing with those whites lower on the station scale.

WIth all due respect, I don't think many slaves would get "uppity" and start mouthing off to poor whites or whites of any ilk unless they wanted a backside that looked like a road map, like the pictures we've all seen. SOunds like a revision of history to make the horror of the insitution less horrible than it really was. For consumption of people in the latter days who would gloss over the reality of what it meant to be regarded and treated like a thinking, speaking horse or a wagon.