Regarding submitting more than one idea:
You can submit as many proposals as you want, provided that each is accompanied by a separate, signed Idea Submission Form (downloaded from the PDF file on the Wizards site). However, I think it's more sensible, rather than submitting several different versions of essentially the same world, to construct one version that is easily applicable to RPGs, novels, miniatures, and TCGs.
You can submit on lightly colored parchment if you want, but it's really not going to make an impression on the selection committee, since we don't see the originals. As someone here remarked, colored paper won't photocopy as well as plain paper.
Please keep in mind that with the sheer number of proposals we're looking at, readability counts for something. In fact, it counts for quite a lot. I'd stay away from fancy fonts, colored paper, and really, really small type size. Such things won't cause us to automatically toss your submission, but they'll get in the way of our appreciation of its content.
Personally, I expect the number of submissions we receive to dramatically increase as the week draws to a close, and we'll be reading frantically during the next week or so. Anything that eases eye strain would be very much appreciated.
