Frontal Stun Immunity - a community poll...

[Secrets]

If I was making a warrior or SK it'd probably be an Ogre due to stats and frontal stun immunity. in velious, I'd rather make an Iksar due to the AC bonus/regen bonus if I was going pure defensive as a warrior or SK.
Yes, the AC bonus will matter in Velious and Velious has no weapon procs that make up for that. Plus while stunned your weapon's GCD keeps going anyways and you will hit when you are unstunned.

Depends on the class. Trolls make better shaman because of the regen bonus. Iksars come Velious might make better shaman, though, since they'll be able to use the clicky bracer.