Magic is not what Skyrim is known for. It's the Shouts. Which is Thu'um. And that stuff is already complicated. But there is a way to learn more of it, through Herma Mora, but I doubt he'd help. He would definitely watch, however. 

I also wish the college had more knowledge on magic, but the sad reality is Nords do not like it. They have a general distrust for the arcane. So to learn more it would require a trip to the Arcane University. Which isn't very feasible at the moment.

I'm just excited that I can learn something new about the game I love. This stuff is just amazing. Recently found a book I never did find and learned about Ysmir. His legends were the start of this rabbit hole I've fallen into.

Also yes, brotherhood use powers given by Sithis to the Night Mother.