How can I create a Drupal "Page" (not a block) without any theme? I do not want this "Page" to include any header / footer / left / right column. My understanding is that this isn't possible but could I create an additional theme for my site which is just completely blank, and apply this to the appropriate pages? We have a salesman that wants to build his own set of pages within Dreamwever and then I would apply this blank theme against just these pages without impacting the existing theme that is utilized for the other pages.
Try the ThemeKey module.
This module has a number of really useful options; relevant to your question, you can have it use a different theme or a stripped down version of your existing theme on certain paths or conditions.
If your user is going to create pages in Dreamweaver, then just have him upload the files into a subfolder of the Drupal root directory...and they will load completely independent of Drupal.
Drupal Directory == /foo/bar/htdocs/mydrupalsite Drupal URL == blah.com/mydrupalsite
User's DW files directory == /foo/bar/htdocs/mydrupalsite/dwsite User's DW URL == blah.com/mydrupalsite/dwsite
His pages will not be affected by Drupal at all. You just have to be careful when upgrading/updating that you leave his folder structure intact.
With this method, you don't have to do any htaccess redirects or anything like that.