Frz or Andrew might have a better answer for you, but from my understanding of c5, the dashbaord pages are linked to some php files. However, nothing is stopping you from deleting those pages and creating new ones.

If you go into the Site Map, you can check the Show System Pages. You can delete/add pages from there.

If you wanted to customize the pages, check out the ../concrete/single_pages/ folder. That's where most of the php files I mentioned are located.

Centralizing concrete5 is one of the few tricks that we're not giving away for free. If you join the hosting partner program (more info here)
http://www.concrete5.org/help/support_and_partners/c5hosting_partne...

you get access to a white paper explaining how we do it on our own servers, in addition to all sorts of other benefits.

In terms of locking down parts of your dashboard, the permission system you know and love for public facing pages is actually running behind the scenes in the dashboard as well.

If you go into the sitemap and click "show system pages" you can view the dashboard pages in the sitemap, and edit those pages the same way you can other pages including permissions