"The GODHEAD is LIFE itself, and his Omnipresence makes all beings and things active and living"

God is not life but conscious existence ("I am"). That's a huge difference. It's associated with life, as God of living, only because only living beings, as mirrors of consciousness, are capable of realizing it and reflecting it back at itself. Also, omnipresence means everywhere -- there cannot be a speck of dust or an inch of space where God is not. Omnipresent God cannot be side-by-side no matter how close, immanent, or transcendent. And that makes God identical with everything.

"returned to the perfect peace of His own unique Ineffable Self, after producing IHOAH, Being-Who-Is-Was-and-Will-Be"

Do you mean that manifested YHWH is that "Being-Who-Is-Was-and-Will-Be"? If so, that's not true. Anything created is not permanent. In either case, God never departed from his essence, so there was no returning to.

"‘God’ is therefore considered to exist in two aspects, one transcendent and unmanifest (Elohim), and another immanent and manifest (Ihoah/ Jehovah/Yahweh)"

Sorry, but this is also not true. The manifest and unmanifest are identical. As I said in my other reply to you, chicken is in the egg, and egg continues in the chicken. I know that it's a very crude analogy, but there is no separate Elohim and YHWH. Or God and world for that matter. And this is knowable.

"an ultimate Ground of Being, conceived of as a self-contained emptiness or nothingness, complete in itself"

It is conceived of as such only in circles that arrived merely at so-called formless realms. There is the awareness of absence. But that is not the true nature of God, or better said Reality. The "Ground of Being" is full to the brim. What is empty, are merely concepts.