Actually, that is exactly what is admitted in your arguments.
To accept the authority of the Church, at any time is to accept its authority at all times.
To deny the authority of the Church is to deny any and all authority of all entities, leaving all Christians adrift in a sea of confusion and contradiction.
It seems in this and other posts, you reject Catholic Church authority and concede it in others.
Though there were some in the Church who disputed, debated and may have even rejected the Apocryphal books, as it stands and has stood for centuries, those books are a part of the canon of Scripture because the official teaching and declarative voice of the Church has spoken. We can be sure that those books are Scriptural as are all the others comprising the Catholic Bible.
This inviolable authority was instituted upon whose authority? The magisterium? That's convenient.
"Just Because We Say So" as holy writ. What a concept. Paul rebuked Peter in the Bible. You regard him as your first Pope. He didn't accept Peter's authority in that instance, rather he upbraided and corrected him.
The Church of Rome would do well to accept rebuke and correct its ways as did Peter. Instead, those with legitimate concerns over corruption and immorality and bad doctrine have been met repeatedly throughout history with arrogance and being outcast and even murderous rage.
This is not the reaction of a Godly institution. An institution that won't purge itself of open Sodomites because it puts more faith in it's own "because we said so" as far as their being priests than it does in the Bible that utterly condemns such behavior in any man or woman, let alone one purporting to represent God.
You do understand that there are four general branches of the orthodox Christian church and they are not all in communion with each other. The Roman Catholic and Western Syriac churches are generally in communion, the African Coptic and Eastern Syriac (together known as the Oriental) churchs are in communion, the Eastern Orthodox not generally in communion with the others.
They are separated by doctrinal and other differences going back to the time of the Roman empire, mostly due to differences in view of Christology. They also don’t even agree amongst themselves as to canon. I’m still not quite sure where this idea of some kind of universal church authority comes from, because there has been no univerally agreed to authority for centuries.