I'm no expert on the American South, but my understanding is that plantation houses were massive. I always compared them as the American answer to the British country houses of the aristocracy. Don't forget, you have a LOT of people to house...
You'd have the main house, for the master, the mistress and their children and other family (if there was any).
You'd have the house-servants, who had their own quarters inside the house (probably downstairs).
You'd have the kitchen (sometimes set away from the house, for fear of fire).
You'd have the slaves quarters.
The overseers quarters.
There was a lot of stuff there. Plantations were not small. If you want an example of a plantation house, check out "Mount Vernon", which was the house of George Washington. The entire estate is absolutely massive! I've been there myself, and it took me ages to walk around the entire place.
As far as I know, the master's main job was to look after the money-side of running the plantation. A woman (his wife) wasn't really expected to work. She might sew and visit and make friends, but that was really it, I believe.
Courtship: I understand that when the girl's being courted (or basically hanging around) with her man, she would have had to be accompanied by her mother/other lady. Why? I also know the boy asked for the parents permission for the girl's marriage, but what if the girl wanted to do the asking: Would she have any power or say-so or would she just have to wait until the boy made the first move?
The 'mother/other lady' (perhaps an aunt) was the chaperone. Her task was to protect the young lady's honour (ie - virginity). She was there to ensure that the young lady did not drink too much (if at all), that men did not make unwarranted advances towards her, and to make sure that she didn't get raped.
Did rich plantation boys work at all? Supposed a guy was going to work in a school as a teacher, but would that mean he would have to be middle-class instead? Suppose his father was a doctor. Basically, what made a higher class person different from a lower class? Who were the ones who owned plantations?
I don't think I can answer this, but those who owned plantations were probably farmers to begin with, who'd struck it rich, and were able to expand. I don't know if that's true or not, but it's what I think. Others might be able to tell you more.