[geofft]

(1), (2), and (3) are true of Certificate Transparency.

(1), (2), and (3) are true of a system where a single trusted coordinator gets to order (and perhaps reject) transactions. A slightly less anonymous version of any electronic stock exchange would count.

(1), (2), and (3) are true of the Debian apt repository.

(1), (2), and (3) are true of any game without secret information, like chess or Go or Pretty Pretty Princess.

You could call all of these "blockchains," but I think that makes the term so generic as to be useless. If you want a national public ledger, that sounds interesting, but please call it a national public ledger, not a blockchain.