Nervous Larry-
The time limit for a submitted VHS portfolio is ten minutes. If you're going to submit anything on VHS, make it from one project. They really aren't impressed by compilations of your best camera work and effects set to music. But sending in one good scene could be fine.
Oh, and copyrighted music isn't a problem. There's no profit being made on your part.
Regarding the scripts, you can send one in as a portfolio by itself. But if you do that, then you can't send in a VHS portfolio. There's a page limit on those, as well. I think the choices for the types of portfolios to submit are: VHS/DVD, scipt, short story, storyboards, and photo essay. Each comes with its own limit that you'll need to look up before mailing it out. Also with the portfolio is an essay of up to 4 pages about you, a life-changing moment, film, etc etc.
When to apply: if you want to re-take the SATs and hold out for more financial aid, then apply regular decision. For the record, though, I got in early decision. Choose whichever one you want, but if you apply early and don't get in, then you can't apply again for regular.
--alan