The Avatars
When Leo first met the Avatars in his vision quest 7x07 "Someone to Witch Over Me" he seemed to not know who the Avatars were until they explained themselves. He was once an Elder and all the Elders knew about them and so did high level demons?
When Leo revealed himself to piper and her sisters why didn't Leo just tell the sisters he had no choice that he joined the new power (Avatars) in order to get the powers to save them and without it they would have died. Then claim he never asked for it. That way let the sisters take it up with the Avatars. Instead of coming out hard core saying hes an avatar and looking all guilty.
Did anyone notice in 7x09 "There's something About Leo" that phoebe hit an energy ball thrown at them with a baseball bat and actually bounced it back to the demon. How was that possible? Shouldn't the bat have exploded?