Tesla will not know. Until Tesla flips the switch, neither third party nor Ford (if they existed) adapters would work. After Tesla flips the switch, both third party and Ford adapters should work.
At least that's the way it looks right now. The adapters don't contain any electronics; they're...
Ford internal is not a globally recognized certificate authority. If they're using their own internal certificate authority, then all HTTP clients would have to have that certificate authority hard coded as one they should trust. By default, typical HTTP clients (web browsers, mobile phone OS...
The regular Tesla wall connector only does 48 amps, but they make a High Power Wall Connector (HPWC) that does 80 amps. I don't know how common they are for public access out in the wild though.