1. How big a deal is “an immortal demon, wreaking horror and bloodshed upon the world”?
Morgan seems to think that ensuring this doesn’t happen should be your top priority, but he’s biased for obvious reasons. If you feel increasing the probability and/or magnitude of success is worth risking the worst outcome, that’s a valid decision.
2. Can the ritual in someway counteract that? Any specific bonuses, or things that are stronger against demons, or more helpful in a world where one is running loose?
Nope.
3. How would multiple rituals (separately interact)?
They wouldn’t.
4. An ideas at all around probability of other people doing a ritual like this one? Across the entire world?
Morgan seems to think that ensuring this doesn’t happen should be your top priority, but he’s biased for obvious reasons. If you feel increasing the probability and/or magnitude of success is worth risking the worst outcome, that’s a valid decision.
Nope.
They wouldn’t.
Possible but unlikely.