Indeed, it is a typo of `public key`. What I mean is that your identity is your private key. And no, you won't have a new IP per network.
Your IP is `fnv1a(ip || index) when index > 0`. Which changes your IP in all of the networks. That's why we also implemented MagicDNS. You can just use your `user.ray` name. The daemon handles IP changes.
NO. You will ONLY have to rotate your IP if you join a network in which there is a collision. 1 in 4 million chance. If that happens, it's ok. Ideally you are using magicDNS and don't have to worry about IPs or just use the IPv6.