We as SharePoint architects would like to be able to leave notes on pages, guiding site admins on how to work with those pages.

Since there's no way to prevent admins from removing or editing specific parts of a page--it's all or nothing--they might accidentally delete an important web part. Being able to leave a big red message that only appears in Edit mode, warning them that deleting that web part will cause trouble, would improve governance and maintainability. It could also improve usability for those admins, giving them helpful tips or historical notes that are always visible when editing the page rather than hidden in a sub-pane somewhere.

Thanks for listening!