Conceptually, this is just a PHP wrapper around a directory structure, right? The pain in the neck about writing a CMS is the User Interface stuff. (At least to me it is)
From what I recall, you're proposing something like this:
A directory structure.....
/www/dc.com/html/mainsite/pages of stuff
/www/dc.com/html/non-published/pages of stuff
/www/dc.com/html/includes/ header, footer, css, images, etc.
/www/dc.com/html/admin/ admin programs to promote content, preview it, etc.
with a control php script to read and display requested pages, but not unpublished or removed pages. Something like:
That would read all of the mainsite directories and pages to create a link panel plus display the requested page. Is that about right?
If you can live without WYSIWYG page creation, this should not be incredibly difficult....for someone else
Seriously, is this the concept?