Who can do what?
The permissions model for Simple Team Pages is pretty simple and generally centers around page-level permissions.
Effectively that means, any user with access to a project (Browse Project
permissions to be exact) is allowed to create, edit, delete, and view pages in that project. That is, unless a page is locked down to specific users/groups/roles, in which case, the user must match the permissions of the given page to be able to access/change the it.
The exception to that is special permissions granted to administrators and page owners.
NOTE:Currently, it is not possible to restrict who can add/edit/delete pages at a global or project level. It is however something we have on our roadmap for the future.