1. I don't think so. The Dark Urge has the ability to be very distracting. It doesn't allow pro-social backgrounds and you may be, in practice, locked out of romantic relationships and companion plotlines. The Dark Urge is the star of the show and has no need for any of that.
There might be towns/places hostile to you as well, which denies you even more content.
2. Yes, because I currently believe the Dark Urge isn't actually a person. They're a fragment of some dark power. Larian may be baiting us with the Bhaal theory, or they may not. However, if it's not Bhaal, it's not necessarily something less evil.
My go to theory for the moment is that it's not Bhaal, but Bhaals power. He's a quasi deity. Less powerful than as a god, but where did that power go? Either it full on possessed someone (Dark Urges) or it was fragmented and those fragments possessed multiple people. I guess that power has kind of an own will, testing Dark Urges or multiple people on who might be worthy to become food for Bhaal to make him powerful again or to replace him.
But I still think you should be able to play him as good. Trying your best that is.
