I plan on adding nearly a new site to my current Drupal site, because it will be the same theme, the same DB, and really the same functionality. With this, I have a few questions to see if I can do what I am looking to do.

1) Make it so that if someone clicks on the primary link to the new division of the site, all of the links in the primary links disappear and turn into only links derrived from the new division. ( Maybe something in the php snippet sections? )

2) Grant permission for specific people to edit these new division pages. They should be given access to modify these pages, but not the original pages. (I was thinking this can be done with roles?)

Thats all I can think of for now. Any suggestions or input would be great!