Just as "grist for your mill," are you aware that sodium bicarbonate is the primary alkaline buffer in the body? It is true we do not "eat" it directly, but the body produces it "directly" from the things we ingest. That seems awfully "natural" to me.
My study of the matter is that the only time it produces the negative health issues you listed is because of the cleansing, i.e. detoxifying, effect it has in/on the body.