Multi-signature is still quite centralized solution if the curation account is managed by a small number of accounts and if all parties quit, the wiki will die. I don’t understand how you would give every infrequent editor access to that account and by doing that somehow prevent vandalism. The change history is also less useful if all editors use the same account.
I was thinking about posting patches as replies to the post or to another patch reply and having a parser read and apply those patches (and preferably cache for future request) to the first revision. The open questions are the patch format, how to tag the first revision as a wiki page, how to pick the current page revision and what kind of UI would make the revision tree readable for less technical users.
Yes, the number of people involved with a multisig account is usually relatively small to make it easy to manage and I suppose there is the risk that everyone could abandon ship at some point without leaving any replacements in charge. About the change history, that should be traceable by the public keys of the signers, I think.
The public keys of the signers are known and should be traceable but what if multiple accounts use the same key for example if the editor’s account is managed by a vault which manages many accounts and all accounts have their authorizations set to the vault account’s name.
Yeah, I guess that's the limit of traceability using the public key. :)