Upload model to dropbox or box.com and share a link please. See if we can help you out before your deadline. Any "complex" model slows down when shaded. If it's unreasonably slow then you'll have to do something about it. I almost always navigate a complex model in monochrome mode. It's because SU is a total arse and doesn't like anything "complex". How dare you model anything more than a cube?! Upload model and I'll have a look.