Hey Chris, not sure what all the sandbox pages are for. Is there something you're working on that can't be done on the pages proper? If there are major changes you're thinking about, it's okay to ask about them in the Special:Forum.
Pretty much the latter. In the case of the walk-around character articles, I'm playing around with the changes I want to make to each existing article: how they're formatted, what pictures to use... When everything's said and done, I'll then bring these changes over to the existing page, after which point I'll delete the sandbox version. Same with the Jeff Moss sandbox page I just started; as a Moss fan (as if you didn't already figure that out, considering who my favorite characters are), I think he deserves a more detailed article.