Arcane does not include Psions because Psions do not draw their power from the weave. You're correct about Druids and Priests, though, because Priests draw their power from their respective deity, as Druids from nature.
Also, in the future, just make sure you post rules questions in the Rules forum (with the appropriate Marshal type in brackets):
"[Rules] Barbarian Arcane Intolerance."
You're not in trouble, I'm just letting you know.
I'm answering this as a New Player Marshal, since you still count as a new player.
OOG -- Jeff Balla