Any idea on their conversion rates? God-like or newbie-like?
Imo, balancing NPC priests is next to impossible. They are far more likely to be either way too powerless or way too powerful. If they can't be arrested and they have too good an oratory skill, then no IG religion will be able to compete with them and they'll just takeover everything. On the other hand, if they can be arrested or if they don't convert fast enough, they won't really represent any kind of significant threat.
Without temples and lords? I don't think they will be that effective at the preaching game. Also, I doubt their purpose is to screw with us directly at present, so I would be surprised to see daimon worship inspired revolts anytime soon.
