Well, Nehrim isn't SUPPOSED to be played like that. You're right, it's not linked to Oblivion, because it's a Total Conversion. You're not supposed to have them linked. I seriously doubt the developers are going to support something just for you when you created the issues yourself.
You should treat Nehrim as a whole new game, because that's essentially what it is. It just uses Oblivion's engine and resources.