It is very late in this thread, and you are going over matters already discussed, and asserting things the Church never taught. Read the Nicene Creed:
. . .And in One Lord, Jesus Christ, the Son of God, begotten of the Father before all worlds, Light of Light, Very God of Very God, begotten, not made, of one essence with the Father by whom all things were made, who for us men and for our salvation came down from Heaven and was incarnate of the Holy Spirit and the Virgin Mary and was made man. . .
The begetting of the Son refers to His eternal ontological source in the Father, not to the Incarnation, even as the procession of the Spirit from the Father refers to His eternal ontology, not His temporal, economical manifestation in the world.
Some of the Fathers indeed paralleled the eternal begetting of the Word with the Incarnation in formulae like "Begotten of His Father without mother, and of his mother without father," but the primary application of 'begotten' to the Word is, as in the Creed, the eternal begetting from the Father.
I was there for the earlier discussion.
"Read the Nicene Creed:"
You posted the old creed, that was used for a long time before it's modern version appeared. I believe that one, not the modern version. The original creed doesn't even mention the timing of the begotten part, except to say it was before all world's. That's acceptable. That came in the old creed you posted. As I said, at some point God must have first pondered creation and that's the earliest point "begotten" applies, no sooner. Before all worlds is fine.
The new creed says eternally. That is neither fine, nor acceptable. It is illogical. As I pointed out, those who say God is timeless are effectively saying God can not exist. The word eternal in that case is also meaningless, because there's no time. God must exist in time. Existing in time requires sequential events. That means God could not have begotten, before He decided to create. The word "beget" is an action. The verb, "to proceed" is an action. Neither of those are nouns that would refer to "is", or "to be". An action can never be eternal, only God's capacity to act can. That capacity is part of His nature.
"of one essence with the Father"
This only applies in Heaven. If you wish to apply it to this universe, that can be done, but then we are all of the same essence and the point becomes meaningless. It's in the physics.
"The begetting of the Son refers to His eternal ontological source in the Father, not to the Incarnation, even as the procession of the Spirit from the Father refers to His eternal ontology,"
I covered that, above. To beget is an action. Capacity is a noun. Jesus is not simple capacity. Spirit must have a physical foundation, or machinery to support it. Spirit does not and can not exist on it's own with no physics to support it.
"even as the procession of the Spirit from the Father refers to His eternal ontology, not His temporal, economical manifestation in the world."
There's no point in referring to the Son as simple capacity, or ability to act. It's the particulars of the action that count. In the case of the Son, both the Father and the Son acted as independent free will agents. Jesus acted exactly as, and under the conditions of, a man. The responsibility for those actions were God's. Note, Jesus did not know, or understand what the Father knew. He was born empty as any man, learned from that point, and was taught by the Father.
"Some of the Fathers indeed paralleled the eternal begetting of the Word with the Incarnation in formulae like "Begotten of His Father without mother, and of his mother without father,""
The keyword is some. The original Creeds contained: "born of the virgin", "made flesh in Mary's womb, and born of her", "born of the virgin Mary", ect... , as does the modern version. I'll note also, there's no miraculous, "like a light through glass" birth either.