Shouldn't the server always have authority to prevent hacking?
From observing other games, this is what causes rubber-banding, I would assume. When you lose connection, the server doesn't track your movement then resets you to where you were when you lost connection. Wouldn't you teleport on the server if the player had authority? Couldn't you also hack noclip by setting your location with an external program?
I understand that you want to have the client move instantly, but this seems to come with some vulnerabilities.