If someone selects public on their event it would be great to create a request for public calendar request. We would give a sub-admin the permissions to approve or deny the request for that event to appear on the public calendar. If they approve the request the event would of course show up on the internal and public calendar, if they denied the request it would only show up on the internal calendar. The denial have to work differently than other denials so that it would not interfere with the pending approval process of the event.