Two weird LTE auth questions that I'm sure someone here knows:

1) My understanding is that the mutual auth means relying on a SIM private key. But can't phones without SIMs get onto networks for emergency calls? Or can that be done without full authentication?

2) Is there anything at the protocol level stopping multiple identical SIMs joining the same network (private, unfederated) network? Multiple devices with different IMEIs but the same IMSI and cryptographic material