Generally speaking I had no problems with most enemies, not even around the dreaded 13th... They can't hurt you if they can't see you; sneaking rules.
By the way, did anyone do the quest in that one city to the right of imperial city (dunno the name), where you have to find a painter? What they do with the graphics there is pretty damn cool. If you haven't seen it, go look around, speak to the shop keepers...