Um, Rodriguez himself said they shot the comics *in their entirety*, and these images were pulled from The Making of Sin City book. So, yeah, it's hardly a baseless assumption. If he says he shot the entire film, and the Making Of The Movie book has images of characters in scenes from the comics (but not from the theatrical release), one would *easily assume* these scenes will end up in the extended versions he's promised us.
I have no idea who the guy is, or who the woman that plays Hartigan's wife is. But there they are. Their names will probably be on the DVD. There are also images of Marv visiting his mother in the book, and I don't know her name either, but you can tell the scene was shot.
Where did you read all this talk about him not even being an actor? Another message board or an actual article?