So good so far.
Jesus was a person, with two inseparable natures, not mixed, mingled or confused.
Yes, Jesus took on Mary's flesh.
That would be God creating God.
Really! you bought that line?
Sin is a voluntary immoral act either of word, thought or deed. The simple concept acknowledges men can 'work' in concert with God's will for Sanctification. The effect of Adam’s transgression is a deprivation of God’s presence; He removes Himself and His justice. The Thomistic view of this removed justice is called ‘original justice’. Since all life emanates from God the punishment is death, both spiritual and physical. There is no “remaking” of Adam’s nature, nor is there a “remaking” of Adam suggested in Scripture. God does not re-make His creation into sin itself; rather he deprives us of His face; such a God would be a perverse being. In ‘re-making’ our nature into sin would suggest that God punishes mankind for His own act of creation - an absurdity.
The problem with "headship," (more properly described as “Federal Headship), is it makes men the actual thing we call sin, which we aren't. It is built on the concept of “once saved always saved which necessitates the removal of Mary from God's plan for our redemption. With your concept of "headship" Mary can bear a man who is sin yet remain the Personification of the Word. This concept has sin hanging on a cross as the Personification of God's Breath produces reparations for the sins of man is an absurdity. The Theoandros is completely lost. The reformer cannot abide in Mary (a human) becoming an instrument of God’s plan of salvation.
Federal Headship and sin nature implies that God judges us by our father. That is God ‘inputs’ sin the children simply because they are prodigy. If this were the case then we wouldn’t owe our salvation to Jesus Christ but to our fathers. We could wipe out sin through DNA alterations. It also implies that God does not love; instead he creates us evil then allows our fathers to pass on this evil through his flesh. The small problem with this is that we receive our flesh from our mothers and we receive blood through the quickening of life, not from the father who only provides the ‘spark’ of life. Jesus Christ then is left with the unenviable task of simply covering our putrid sins by lottery so that the stench does not offend heaven. Federal Headship means we are condemned by proxy for the sins of our fathers, and by proxy we save our children by being just.
Then you have the perfect Lamb of God is begotten of corruption. That might suit a particular being, but not Catholics.
Do words not mean anything in Protestantism? An emissary of God formally hales Mary and tell her is, in your words 'fully favored' holds no special significance to you. The grammar holds, “
completely, perfectly, endearingly endowed with grace." But then you need to contend with Mary's words in Luke 1:34.
“[The] Greek present tense used for Mary’s words in Luke 1:34 corresponds…to the Hebrew and Aramaic active participle indicating a permanent condition. Mary’s words in Aramaic were ki enneni yodaat ish, the yodaat indicating a permanent condition of virginity” (Warren Carroll summarizing and quoting from Manuel Miguen’s “indispensable” work, The Virgin Birth: an Evaluation of Scriptural Evidence (p.81) in The Founding of Christendom, Vol. I, p.310).
Manuel Miguen notices that the expression has obvious Hebrew idiomatic roots. “It is well known that the biblical language a paraphrase to describe a virgin stricto sensu [om the stroct semse] is this: “a woman who did not know man” (Gen 19:8; Jude 11:39, see verse 37; 21:12; basically the same are Num 31:10, 35; Jude 21:11 cfr. Wisdom 3:13) – which, incidentally, shows that the same expression in Luke 1:34 points to virginity proper. These are all passages where the Bible refers to women who “did not know man.” Miguen continues to point out how interesting the present tense is never used with regard to virginity. Miguen further suggests that the Greek translation makes the best of the Aramaic it can by using the Greek aorist tense. [source
The virgin birth : an evaluation of scriptural evidence : Miguéns, M. (Manuel) : Free Download, Borrow, and Streaming : Internet Archive]
Consequently, we hear Mary say to Gabriel, (in my words), ‘How can this be when I did not know a man, do not now know a man, and will never know man. ‘ Thus, Mary vows virginity in the presence of a Divine Messenger as well as expressing her own astonishment.
JoeT