hmmm - to be honest - i'm no nurbs expert, but i think achieving that is going to be difficult. generally people tend to stay away from booleans because they can really mess up your geometry, so getting a bevel effect on those edges may be extra confusing.
i don't think it has anything to do with normals.

again, not to go on, but why do you want to make it in nurbs - is it for school? if it's just because you want to learn nurbs than i might focus on something a bit easier, but usually people tend to model in polygons and only use nurbs if they absolutely have to.