Something completely on the side of what you're asking for, but still probably relevant: One of my main problems with the numerous dungeons in Oblivion, was that my character had no good roleplaying reason to enter most of them. That's why I added (semi-)random merchant quests in Enhanced Economy, where merchants will ask you to find various items. For each item you will be given the name of up to 3 dungeons where the item can be, and the item will be randonly places in any container in one of the three dungeons (thus different on each play-through).
I find that dungeons are much more interesting to search through when you have something you're actuallu looking for too.
I agree and support this completely. When I read about the merchant quests in EE, I was a bit skeptical. Turns out, playing them feels a hell of a lot like playing a real Radiant AI. I really enjoy them now, and I wish more could be added to the game for the very reason you mention - maybe even a second tier to the merchants. I mean, really, not every character is a thievin', killin' Nord or Bosmer.
With your merchants mod, you can really play as a member of the local guard or even the Imperial Legion.
You could use the same scripting system to give the player quests associated with the churches - real pilgrimage quests, for example - or maybe have the Counts/Countesses give players random quests.
I've actually been playing with issue in my game, reading up on questing, and having NPC's appear in the game for the sake of quest, then disappear afterwards. Using a random level generator, an NPC appears in at the King and Queen tavern. She gives the player a simple quest to find her brother who has gone missing. I've been limiting it to one location, but why couldn't you have the body randomly appear in one of two or three locations?
There's not much to the quests right now: the NPC appears, the player gets the quest, goes to the location, finds the brother, returns with a quest item artifact (a ring, for example). Ring is returned and NPC disappears from the game. Not a lot of meat and potatoes, but if I can add eight or nine of these small quests, the game becomes a lot more dynamic.
MB