I haven't changed. If you say that God cannot die, then either Christ did not die (that's Docetism), or Christ was not God (that's Arianism). Both are heresies.
You appear now to be agreeing that it's best to be specific about which person of the trinity we are referring to.
No, it is best to state the truth. And the truth is that Mary is the mother of God, because she is the mother of the Second Person of the Trinity, and the Second Person of the Trinity is God.
-A8
So, why do you keep insisting that the Father is not God?
Did the 2nd person of the trinity exist before Mary?