Do you have to do the College of Winterhold quests to have access to Master level Destruction spells or can they be bought from a vendor?

Need access to the college, a quest is required to get them.



Edit: Also, while they're awesome, I personally only think the blizzard master spell is worthwhile. Lightning is amazingly cool but unreliable, and fire can nuke anyone you have with you. Blizzard has a fantastic area coverage effect that drains health.

What are the highest rank I can get without the College?

Now that is something I wish I could help you with, because I'm curious about that myself. Highest I've seen outside of college...I think are one step above the basic spells. But that's only what I've witnessed, and it might be wrong.

You can, however, get a few higher level spells as randomized loot if you're incredibly lucky.

Look here:
http://www.uesp.net/wiki/Skyrim:Spells

It looks like you can get a good selection from a mage in Markarth.

That's what I needed. Thanks.