Rotate keys: old key signs an event indicating that it is being rolled into a new key.
Multiple keys: nothing to change. Works like that now.
Recover your identity: Well, if you want a well-known identity use NIP-05/NIP-35 and just change your .well-known/nostr.json file to point to your new identity, the one that hasn't been stolen. Hopefully nostr clients of your followers will respect that (who knows what programmers actually will do).
I think these problems are easier than you think they are.
Multiple keys: nothing to change. Works like that now.
Recover your identity: Well, if you want a well-known identity use NIP-05/NIP-35 and just change your .well-known/nostr.json file to point to your new identity, the one that hasn't been stolen. Hopefully nostr clients of your followers will respect that (who knows what programmers actually will do).
I think these problems are easier than you think they are.