Sitebuilder keeps a copy of your site on its local database therefore it will allow you to edit your site as many times as you wish.This means you may add, removed, or edit templates and content as many times as you wish.
However, once you elimiate Sitebuilder to edit your web (by means of Web Expression, FrontPage, or Dreamweaver, to name a few editors) it will not see the changes you have made with the third party HTML editor and it will simply overwrite these changes if you try using Sitebuilder as your publisher.