Hi Dennis: I think we probably agree on the Holy Spirit and the role of Advocate / Paraclete; neither a simplistic stability a whimsical free-for-all.  The Spirit guides and teaches as and when the need arises but new doctrine, a la Mormonism, is antithetical to that guidance.
While I agree that theology is foundational to teaching, in the early ages, at least, it was driven not by Scripture but by the praxis of the faith passed on by the Apostles.  The Trinitarian Dogma is pre-Canon and is supported by Scripture vs being derived from it.  As the Church gained reprieve from persecutions, thoughts of God's nature (especially of Christ) became of greater concern but if you ask even a fairly well educated Catholic whether Christ has two wills or one, I would suspect most do not know, though I suspect they know that an answer exists and where to go to get the answer.
Re REALITY, not even all n-Ps agree on its nature.  I see n-P and Aristotle's philosophies as both / and v. either / or.