Did I say I was confused?
How do you know that the ground of being is Personality? You quote the opening of Genesis, which is merely one source, and a very ambiguous one at best. Since the Hebrew word Elohim is plural, it presumably cannot refer to a single personality.
What follows is your attempt to understand the mystery, seemingly from an exclusively Christian perspective, with the rational mind. All human minds are limited in this respect.
Why is it vital to understand something which may not be true? Another way of putting what you say is that the original nothingness had the potential to manifest the creative principle (God).
Christian scripture may well say that, but I would be interested to hear of any “other ancient religious texts” which say the same, if you can find them. The point of my article was to suggest that Christianity is somewhat isolated in its stance. You may think that “nothingness was at best only ever a metaphysical anti-concept without any relatability at all”, but that is in fact what is claimed by the other traditions I referred to.
God is indeed the eternal antithesis of nothingness, as I stated in the article. He/it is the absolute Oneness which emerges from the nothingness.