In the video, there is a note along the screen stating that when working with templates, the content area should not be added to an editable region.
Yes, if you add an editable region to the template, it means the user can edit that area of the template.
Power CMS does not create any menus. you would need to create the menus. see this tutorial for details on using Power CMS templates and creating a results page to show new pages as they are created:
this technique can also be applied to a menu system