First question: Tree (vertical with sub-levels) option in the Navigation widget provides you with the functionality to limit the pages showing, but they the menu is based on your current page ordering. To do a menu where you can apply different ordering logic you can create a custom widget for the case.
On your second question: go to the page you want to hide from regular users and expand its Actions
menu then select Permissions
and from there you can edit who can view this page.
Hope this information is helpful to you.
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items