I don't think the Urn is skippable as Eamon gets pretty important.
Also yes there are several outcomes with Elves and Werewolves. Though to side with the Werewolves you need a pretty big Coercion stat and pick the evil option. Because siding with Werewolves needs something pretty evil.
There is one accepted "perfect" path and then several inbetween, with siding with Werewolves viewed as the evil option at that.
The other paths don't have this by the way, they're more purely do the evil thing or do the good thing.