I do have a few points of contention:

Vatican II does not put the authority of Scripture below the Church. It says, “The Magisterium is not above the word of God, but subservient to it” (DV 10). It is because of the Holy Spirit that the Magisterium is able to faithfully interpret and announce the Gospel of the Lord.

As for the development of Doctrine. The deposit of faith remains the same, God’s Word is definitive revelation. “The Christian dispensation, therefore, as the new and definitive Covenant, will never pass away, and no new public Revelation is to be expected before the glorious manifestation of our Lord Jesus Christ.” Divine revelation itself does not grow; however, our understanding of it can grow. Surely you accept this; otherwise, you would spend your time doing scholarly research on revelation.

‘Both and’ has always been the Tradition of the Church. Take a look at all the Christological dogmas and Trinitarian dogmas of the Fathers. They always choose the both and. God is both three and one. Christ is both man and God.

Van Till’s critique of the Catholic doctrine of original sin is interesting. Keep in mind, however, that for St. Thomas, one’s moral character is ontological. Virtue is an accidental change in a person. I’d need to do more research, but I suspect that what Van Til describes a dichotomy between viewing the fall as an ethical or ontological problem is false.