I am also having an issue in which I am unable to physgun and remove world entities, despite being a full superadmin and having the admin's checkbox unchecked.
We sometimes have npcs and other things lose their ownership. In one particular case two manhacks became invincible and were running around the server mauling people and the only way to remove them was to reset the map, while several people were building. Other things spawned by scripts and such are also unable to be touched because they are owned by world. The supply drops from J.I. Defense is a good example. Also, entities stuffed into crates with the crate tool also have this problem once they are released. And as an admin I can't clear them out without resetting the map. Do I need to reinforce the admin's bypassing restrictions through a svar/cvar?
Also, should players be able to clip through admin props?