I've been playing for 46 hours. I've not done much with the main quest line either. Though, I have scratched the surface of the mage's guild and thieve's guild. I don't want to far into them yet.
I'm trying to cut down on my quest list as best as possible. It seems though, every time you talk to someone/read a book/over here someone say something (seriously, I ran by a guard who said something about seeing a dragon fly by, and I got a quest to go find it).
Either way, I've at least gotten my miscellaneous quests down to 3. 2 of them are collecting quests and one is bugged, so I can't do it.