This is something we definitely talked about as a part of this program. For now our goal is to launch the Class Representatives and see how it goes. If it is well received on both sides and people like the dialog it creates. If it works, we will talk about expanding it, like you suggested above.
As you can see from this very thread some folks are hesitant about the concept. We too want to see how it goes before we roll it out too broadly!
If I could make 1 suggestion.
Don't have seperate reps for mirror classes. instead have a rep for each skill tree. i.e for Shadow/Sin have a Tanking rep and a dps rep.
for Merc have a DPS rep and a healing rep etc...
This would make way more sense then Shadow and Sin reps.