On the side, I suppose there is a curious detail that has been overlooked in the whole discussion-
The Dark Urge killed
at the end of Blood in Baldur's Gate. They were specifically named
which does have some implications.
Perhaps the main character isn't the customizable "Tav" avatar, but the Dark Urge, and may be related to why the Dark Urge is customizable.
COMPLETE speculation as I've nothing else to remotely back it up, but it IS curious and noteworthy.