How can I make the project pages invisible for any user who is authorized to see the project?

This can be customized by a Project Administrator.

The Project Administrator can set this using these steps:
  1. Click the link 'On' next to Configure, on the top right-hand side of the project home page.
  2. Scroll to the page you want to hide and click the Edit Properties icon. This can be found on the right side of the title bar for the page you want to edit, next to Edit or Create buttons. The tooltip displays if you hover over the tool.
  3. Choose 'Hidden - Visible only to project administrators in configure mode'.
  4. Click Save.