RE: Nathan's different builds:
Looking at the way race bonuses are constructed in Skyrim, it doesn't look like Bretons are really intended to be directly involved in combat. They have bonuses for every magical skill EXCEPT destruction, including a big one for Conjuration.
I still think you could make a decent Mage with one, but if you got off to a slow start and didn't train, I can see where it would be an uphill battle, especially with a physically weak race.