Sounds like an interesting book.
Bump till the bubble heads show up.
China had no missiles capable of hitting the US prior to the early '80s.
We are also supposed to believe nobody in the KGB knew of the fail-safe devices? The KGB was, by definition, infiltrated into every part of Soviet society.
My recollection of the articles and documentaries about the lost submarine do not include references to damage such as is described here. I do remember that during the recovery effort one of the missiles slipped from the tube and gave the recovery people some very nervous moments as it fell nose first back to the sea. They feared the warhead might go off. This all seems inconsistant.
That being said I think there is a good basis to think the submarine was indeed on an unauthorized attack mission, based largely on the USSR navy's recovery efforts being centered a thousand miles from the loss site. I've always felt it likely the submarine was scuttled by members of her own crew to prevent launch.
Worth the time... ping.