1) My experience, for whatever that's worth, is different. When you start working with any sphere on the Tree, you have to deal with its negative dimension in yourself -- what Dion Fortune calls the vice of the sphere. That comes up simply because when you awaken the sphere's energies in yourself, everything corresponding to that sphere becomes more active, including the vice -- and you need to master it or it'll master you. So, no, I haven't had to banish entities on the Tree of Life -- I've had to clean up my own act and do a lot of reflection, meditation, and journaling to bring this or that set of bad habits under control.

2) Well, of course! Pan is one of the great archetypes, and all those are on the Tree. He has a dark face because he represents unassimilated unconscious forces.