Well, it's not that quests change to fit your class, rather that he's joined the assassins guild and is doing their quests
For my part, as thief, I have had a lot of fun rescuing people from the shattered ruins of a destroyed city and pillaging their possessions the moment their backs are turned. The thieves guild quests have been very exciting so far, the last one requiring pure stealth - sneak into a crypt, steal a bust and get out without being seen. If you're seen, you WILL be arrested.
When you're arrested you can pay a fine (based on your bounty, in turn based on what you were caught doing / have done), go to jail or resist arrest. Going to jail causes one of your primary stats to decay by at least 1.
However, I've joined the Blades, so I am wielding their katana - fast with a great reach, good sword
If you time it right, you can back away from a mob keeping them
right on the tip of your sword's reach. If they don't have a weapon they can't hit you