[Alneyan]

Your cities shall burn with our vengeful fire! You should be allowed to give the classical message "We declare war upon your unholy nation", if nothing else; even the AI does that!

On the matter of Pretenders, I don't think the version will matter, though there might be a problem with that Pretender whose item slots were changed (Void Lord IIRC); there is no problem with upgrading a game after it has started, so doing the (virtual) opposite should work fine too.