I want to discuss the self-defense choices of an Dawnguard Sorcerer (Destruction\Restoration (both have damage spell in them with DG plus fear that works on vampires, etc)
(so that's what I'm role playing at the moment).

You have these options:

• Alteration (Flesh, Detect Life\Dead, Paralyze, Candlelight)
  
• Illusion (Calm, Fear, Fury, Invisibility)
  
• Conjuration (Conjure, Bound, Summon, Banish Deadra)

What would you take and why?
(ONLY PICK 1 SCHOOL) I think 3 is enough for me to focus on.

Don't really see any reason I would go with Conjuration outside of Flame Atronachs, but using Daedra/Necromancy seems to be anti-Dawnguard.

Alteration's major bonus from an RP perspective would be the Detect Dead spell, as it would help you smoke out the enemy.

Illusion doesn't seem to be as helpful from an RP perspective., though it could certainly help you if you wanted to hide rather than confront your enemy.

If you look at Illusion as a power you have to give people courage to stand up against evil (Courage spell from Illusion)?
Sorry, just trying really hard (hence I ask) to come up with some reasonable answers to why a Sorcerer would have Illusion because it would be useful to have Invisbility as I won't take any points into Stamina or Health.

As in when charging up one of those master Destruction spells it would be handy to do that while being Invisibile as if I get hit, I probably die (that is my choice) want to be fragile but deadly.

But most of the people are too weak to stand up to the vampires, thus the need for the Dawnguard to protect them.

Also, the Courage spell in a lot of ways is too similar to the vampire powers like Seduction for my characters to see as something she should use as a member of the Dawnguard. Too much manipulation and mind control for her taste. She'd rather remove the vampires' ability to hide than use their same tactics of manipulating others for her own gain.

I could role play a half bad (manipulating for the purpose of good) Dawnguard, perhaps some kind of Sorcerer Assassin type. Using Invisibility and Illusion spells to bend peoples mind for their own good, in a good way, Charm for instance if I don't want to hurt them?