A nomination for book/score would mean a whole lot more for the guys than an acting nod, in my opinion. It's their creation; acting in it is just the icing on the cake.
I think Susan has an excellent shot at a nod. She has one of the most genuinely emotional parts of the show (which is also one of the show's best songs, which she also helped create), and her story of being a corporate whore by day and Broadway actress by night just makes adds to it.
"...everyone finally shut up, and the audience could enjoy the beginning of the Anatevka Pogram in peace."