it won’t be fully fixable until we make a better NIP-44 that includes kind and source info, because an app can take an encrypted blob and sign a message containing it to make it look like an outbound message, then ask to decrypt it
not sure what you mean
an approach to limiting decryption access is per kind but a problem is that you can take an encrypted blob and make it look like something else by putting it in a different kind and with the p tag of the sender to make it appear like it’s an outgoing message + asking the ext to sign the only solution is indicating the kind and sender in the encrypted blob