So, um, what exactly are they there for? You know, the Lord and Lady who have the bodyguards and imply that they're waiting for someone (or something like that.) Are they just there to add realism (Like, not every single building and citizen doesn't center around your party) or what? There are other cases like this, but I can't think of them at the moment.

They are just there to insult you, as far as I know. Just ignore them.

They actually hired soemone when they prgrammed jsut to make a bunch of realism insults and npcs

Althought if you have an awesome thief, pickpocket them, ya never know

Is there seriously anything good from them?

When I killed them with an evil party, I recall the loot to be very poor.

I think I pickpocketed them in my previous game and as Dundee said the loot wasn't worth it. It's like one poor gem and about seven gold or something.

I wouldn't like to kill them just for fun, but [ToB spoiler here] I'm wondering if a Rod of Cursing would turn them hostile.... there's nothing like being talked down to from someone whom you're about to render blind, deaf, and dumb.

Blind, deaf, and dumb.. Myself, I prefer putting them in that sphere (Olituke's? Otiluke? Whatever. His Resilient Sphere) and letting them sit there and think over how rude they were. Of course, when I was playing an evil char I just sent them to a tiny container several miles below the earth's surface.