thought i'd share my experience with my weapon- and armorless playstyle. I always wanted to try a mage, And the Dark Brotherhood robes look pretty awesome. I also like to murder a lot of people in the game, so that fits the theme nicely.
Out in the open, i nuke around, often from quite a distance. Laying waste to a bandit camp from a hilltop is quite the entertainment.
For situations where a lightshow is not done, I reverse-pickpocket nasty concoctions. It's less flashy, but in no way less satisfying. Heh, Ingun Black-Biar would probably agree. Stealing the enemy's weapons and armor is a nifty trick too.
Works a treat. Focus on Destruction, Conjuration, Alteration, Enchanting, Alchemy, Pickpocket and Sneak.
Too bad there is no "clean" Dark Brotherhood outfit to enchant

I guess I will have to train combat skills eventually to get perks, but I'm level 42 now and haven't swung a sword or fired an arrow yet.
What do you think?
