We have these arguments over and over but the facts don't change. Scripture does not support the Catholic's dogma about this. Why must Mary be exalted this false way?
You apparently missed another thread posted earlier today.
in 431, the Council of Ephesus met, under Cyrils leadership, and solemnly proclaimed that Mary is indeed rightly to be honored as the Theotokos, the Mother of God. It proclaimed that from the moment of his conception, God truly became man. Of course Mary is a creature and could never be the origin of the eternal Trinity, God without beginning or end. But the second person of the blessed Trinity chose to truly become man. He did not just come and borrow a human body and drive it around for awhile, ascend back to heaven, and discard it like an old car. No, at the moment of his conception in the womb of Mary, an amazing thing happened. God the Son united himself with a human nature forever. Humanity and divinity were so closely bound together in Jesus, son of Mary, that they could never be separated again. Everything that would be done by the son of Mary would be the act both of God and of man. So indeed it would be right to say that a man raised Lazarus from the dead and commanded the wind and waves, that God was born that first Christmas day and that, on Good Friday, God died.
Calling Mary Mother of God Tells Us Who Jesus Is
She is therefore his human mother.
By this statement, you, like freeper flowerplough, have fallen prey to one of the oldest christian heresies - Nestorianism.
Nestorianism is the error that Jesus is two distinct persons. The heresy is named after Nestorius, who was born in Syria and died in 451 AD, who advocated this doctrine. Nestorius was a monk who became the Patriarch of Constantinople and he repudiated the Marian title "Mother of God." He held that Mary was the mother of Christ only in respect to His humanity. The council of Ephesus was convened in 431 to address the issue and pronounced that Jesus was one person in two distinct and inseparable natures: divine and human.
Nestorius was deposed as Patriarch and sent to Antioch, then Arabia, and then Egypt. Nestorianism survived until around 1300.
The problem with Nestorianism is that it threatens the atonement. If Jesus is two persons, then which one died on the cross? If it was the "human person" then the atonement is not of divine quality and thereby insufficient to cleanse us of our sins.
Scriptures and Catholic dogma are remarkably in agreement on Mary.
This is what's known as the Hypostatic Union. It is the perfect union of the Divine and human natures in the one Person of Jesus Christ. This, and ONLY this, is what is meant by the phrase "true God and true man," or as you said, "fully God and fully man."
If the Divine and human natures were not so completely unified in the Person of Christ, He would either be a half God/half man, or at least not fully God.
If you've ever read Shakespeare, and run across the phrase "Odds Bodkins," here is a recognition of the Hypostatic Union, which means literally "God's Body."
But this is Biblical:
 And when Elizabeth heard the greeting of Mary, the babe leaped in her womb; and Elizabeth was filled with the Holy Spirit
 and she exclaimed with a loud cry, "Blessed are you among women, and blessed is the fruit of your womb!
 And why is this granted me, that the mother of my Lord should come to me?
Luke 1:41-43 RSV
 And the Word became flesh and dwelt among us, full of grace and truth; we have beheld his glory, glory as of the only Son from the Father.
When the Apostle Thomas exclaimed, "My Lord and my God," did the "my Lord" part only address the human "side" of Jesus, and the "my God" part only address the Divine "side?"
Mary, the Blessed Virgin, derives her identity as the Mother of God by virtue of the Hypostatic Union. This High Priest we have is truly like us in all things except sin. He isn't just God in a human body, or any variation thereof that would make Him less than Who He is.