RLY RLY?
.."* The only 100% secure computer system is one that’s not connected to a network … and switched off … and encased in concrete … at the bottom of the ocean."
You have no clue what you are talking about, as evidenced by the fact you used the phrase "the only 100% secure". NOTHING is "100% secure" when applied to a broad threat model. If you think that your definition of 100% secure is in some way actually useful, you truly are naive.
You have only implemented prevention systems systems in that model - no detection of attacks or response for when they are in process (or afterwards - when they are successful). In theory only the cost of getting the thing off the ocean bed (and a hammer and chisel to get past the concrete) are needed to gain access to your "100% secure computer system".
Security is an fundamentally an economics problem - you make trade-offs in resources or functionality to gain security (or not). Your above model is not only insecure by any sane reason for why you would use that approach, but for all intents and purposes utterly useless and impractical - what's the point of a computer that cannot be used?
I really hope you have no responsibility for anything where security actually matters.