We're excited to announce that we've fully migrated the Xbox Forums to their new home, here on the Microsoft Community forums!
As of today, going to forums.xbox.com will redirect you here to the Xbox area of the Community forums. We've moved all of your existing threads over so you can continue and start conversations with the new forums experience.
We sincerely appreciate the feedback you have provided over this transition and can't wait for you to check out the new Xbox Forums!
You can do any questline if you are a werewolf. When you are a werewolf you pretty much own face. And if you change in secret and change back in secret you can get away with murders. And you can do the Companions without turning into a werewolf, though
I am not sure why you wouldn't want to. The Silver Hand are very tough enemies.
Not if you don't want to. The benefits include being immune to disease (in either human or werewolf form), being stronger and faster as a werewolf but the only downside is no 'well rested' bonus after sleeping. As far as I'm aware it doesn't stop you
from doing any other guild questlines There's a quest for a cure (at least it was hinted by one of the older companion members) but I haven't looked into it.
The werewolf ability has benefits, like 100% resistant to disease, committing crime without being identified, but no, I completed the Companions questline without ever using it, and no, as far as I know, it doesn't stop you doing anything else.