Set which CTA types can be deleted by end users

This would be a welcome change! To get even more granular, it would be great to restrict it to only CTAs they create (regardless of or in addition to type filtering) vs. allowing them to delete system-generated items.

Excellent idea. Even if we rule out bad faith abuse, I've had horrible experiences with users somehow fully deleting a CTA filled with historical data and associated Timeline records. The recycle bin helps a bit (if you catch it in time) but better would be to prevent that kind of mishap entirely with system controls while still allowing SOME self-service cleanup for their own records.