I think the theory is mostly sound. Sure there will be interrupts but if it gets to be a problem, there are talents to help with that and the paladin has a whole aura for that purpose. And yeah, I didn't figure lots of melee classes would be a good idea. Too many ways to screw up melee range and character orientation. So I built a group based mostly on range. Healers don't need to be oriented in any particular direction to heal. They just need to be in range. Only the two dps classes and the tanks need to be facing the mob really and since they're starting at range they only need to make sure they are oriented correctly to begin with. Assuming they are facing the general direction of the target, a couple spells even orient the caster to directly face the mob while channeling (Arcane missles, Aimed Shot). For tanking, a lot of mitigation is passive. Armor, dodge, parry, and blocking are all passive ways to avoid damage and are all based on gear and talents. Plus there are spells and abilities like Scorpid Sting and Shield Block that improve a tank's ability to passively mitigate damage.

I'm eager to see if all this theory craft survives the real world test but I guess there's really only one way to find out.