I like the idea of NMs at every level. I would suggest that they continue to use the runestone method for NM drops. Maybe they don't all drop a runestone, but something unique that can be traded for gear or a weapon to an npc. I agree with the binding aspect. However, I wouldn't want to be required to find someone to help me kill an NM. Call me greedy, but if I see an NM to kill, I want the loot for myself.