Dunmer Lore and ZDawg's quest

[Razorwing]

1. I don't think it's known, so for pragmatic reasons let's say they take on the man's last name.

2. No. Redorans and Hlaalu hate each other. Redoran only dislikes Telvanni, but that doesn't help since Telvanni hate everyone who isn't Telvanni. They're rather xenophobic. Redoran get along well with Indoril, and Hlaalu get along well with Dres . Hlaalu and Dres get along well with the Empire, Indoril is pretty neutral, Redoran dislikes them, and Telvanni of course hate them. I'm writing this off the top of my head, but that's how I recall the faction reactions. Also it's in Oblivion's timeline; Dres changed quite dramatically between Morrowind and Oblivion.

Not all Dunmer belong to Great Houses though and there's nothing to stop an unaffiliated Dunmer from being friends with anyone from a Great House, except of course if that Great House is Telvanni.

3. Hlaalu are the wealthiest overall, due to the profits generated by their trade with the Empire and due to controlling so many large cities in Morrowind and thereby getting taxation. Redoran is less wealthy overall, but there are still rich Redorans, just probably not as many as there are Hlaalu. Telvanni, well, I would say they're a special case because their society is so anarchistic that wealth varies a great deal from person to person. (These are my opinions and may or may not be facts )

4. Not sure exactly what you mean, but if a Hlaalu craftsman moved to the farmland I would imagine House Hlaalu would see him as a traitor, his neighbours would be untrusting towards him, and he would likely earn much less money than if he had lived in a city among his own kind. I know it's fun to make exceptions to rules, but I also think it adds to the overall fun if we can strengthen the animosity between Hlaalu and Redoran whenever there's a chance. There's a lot of venues for quest ideas in that conflict.