Well I'll have some pages that are more like system pages, they need to be there and admin should be able to change SOME of the content.
The first example that comes to mind are custom welcome and exit pages. I have a login and logout redirect plugin that points to custom pages I've created called Welcome.php and Exit.php. User logs in and is taken to a custom welcome page, logs out and gets an exit page.
I created custom templates for both these pages so that some content never changes. The exit page might have future events hard coded into the template so the user can't mess with this. But the admin should be able to go to those pages and fill out the page content which will be their own personalized message and will display on these pages.
About these pages:
These system pages have both hard coded content and space available for personalized message.
If admin doesn't fill out a personalized message there's no problem, other content will show.
(it's ok of someone empties out these pages)
These pages are required and should never be deleted.