The Dawnguard Sun spells are not affected by Augmented perks just Necromage. However Bane of the Undead is affected by Augmented Fire perks.  I'm not sure about AoT. 

Sun damage is it's own effect.

Does completing Missing In Action make Thalmor outside of the ones around Northwatch Keep hostile?

You mean the ones you find randomly along the roads? No. Some Thalmor do hunt you but I think that's after the embassy quest.

Or named ones like Ancano who isn't supposed to be hostile until The Eye Of Magnus. UESP says he's part of the Thalmor Splinter Faction, while the Northwatch NPCs are in MS09NorthwatchFaction, so I guess I don't have to worry about him being hostile too soon.

Since North Wind is the same as Blizzard, as far as I know, is it effected by the weakness to frost/magicka thing? 

No, I tested it with my Cryomancer build and the stone power is not affected by the bug. 

Oh well. 

I'm assuming that North Wind respond to Augmented Frost (And the, uh, other one to Augmented Flames... Sun Flare?), but does it (they) also respond to Fortify Destruction effects like Potions or Shalidor's Scrolls?