My understanding is that the files will be "watermarked" somehow to show that they have been created with a student version. I have never actually tried it.
I think Jeff is right about the mark but I think either way I would contact your VAR just to get a double check on the rules
You certainly should be able to use SW student version to post work on your portfolio. The purpose of it is to learn the software and get a job using full versions so they can keep selling full versions.
I'm not sure what SW student version does, but AutoDesk products do mark all prints, pdf's & other images. This can be photo shopped out for portfolios and presentations. It is additional steps and is a bit of an annoyance but at least its possible.
I had given architectural presentation in school leaving it in and got a lot of negative feedback. Although people claimed to understand I was using student versions of the software, that was a distraction from my work that they focused on.