Re: IC: Elder Scrolls game in Skyrim
All right, so there is interest... good.
As for rules, I don´t know either Dungeon World or BRP; I have something more like Classic Traveller in mind - 2d6 plus skill level. Though frankly, storytelling is going to be more important than good rolls. I´m going to set up the game, write up what rules I have in mind, and then we´ll see. The rules won´t be set in stone, either - if we agree to change them, they change.
Regarding organisations - outright joining an organization and doing series of quests for them might be too much of a distraction from the storyline, however there´s nothing that say you can´t work with one of them on a particular task now and then. And depending on their backstory, characters might actually start out being members of some organisation or the other. The only thing I´m ruling out right away is affiliation with the Thalmor.