Relays don't have to comply. I can run my relay and broadcast your notes all over again. That's why you can ask relays to delete a note but it's hard to effectively have it deleted because your note can be on hundred of relays, that's the point of the protocol, not being able to censor your notes, even if it's you who wants to censor it with a delete.  

 Sure ! I just gave you example that it’s possible and there are def solutions we don’t know yet. Same applies to delete and edit notes