I never bothered with it the first time I played this game through but now I MUST know...
In Curst you meet a woman named Roberta that want's her husband dead. What can you do about that?
The 2 merchants and their legacy...how do you solve this so everyone is happy?
Is there someone you can ask?

Well I reported her to a curst guard captain. Not the nicest thing to do I suppose, judging from that guilliotine on display. :D

You solve the thing between those two by running first to the first one's house and then to the other. Repeat about 2 or 3 times.
Talk to them there, obviously.
At least that's how I remember it.

Are there no other things you can do? I mean
Roberta's husbans kind of deserves it, but I don't wan't to get him killed and I think it's a bit evil to have Roberta executed like that. What would a LG characther do?!

There is another option I think, but I'll be damned if I remember it. Download a walkthrough from the site and find out.
http://www.sorcerers.net/Games/Torment