There is no getting around it. The weight of evidences found in the historical record (and scripture, too) is just too overwhelming to leave it all now to Romanist 'Curia' to "decide". More Newmanesque duplicitous explanation from that crowd (and they ARE good at it, well polished, careful lawyers for their client -- which client is themselves too) is not going to lead anyone to unvarnished truth anymore than relying upon testimony of a criminal as to his own crime-- not when he has had access to evidence (and past opportunity to destroy some of that which may otherwise indict himself) and full ability to intimidate and otherwise tamper with "witnesses" from within the RCC. It's like --- at the end of the day, "tell us what we want to hear, or no soup for you, buckwheat". They don't even have to say it.
Try instead the link I offered, and if you like, skip down to the discussion offered in the last blockquoted portion.
Singular papacy, (along with much of all which is freighted with that) in that there being idea such a thing a singular bishop over all others, should be centered anywhere, including Rome, was not the original form of governmental structure of "the church". Period dot.
Even idea of "patriarchate" had some unfolding and development. With the situation in Rome, it was not originally given honor for singular reason of Peter having been there, for Peter had established previous to time of his first arrival in Rome, the church at Antioch (so much for "primacy",huh? they were "first" before Rome) but for reason that both Peter & Paul had been there, more as senior mentors as it were, then either of them being thought of as "bishop" there (with that idea -- Peter as bishop of Rome --- having been first mentioned only some a century or more later) leaving others outside of "Rome" saying such as the bishopric of Rome due some particular honor for reason of enjoying double-apostolicity, rather than any earliest tradition that all should bow towards that office, more than any other. All bishops were once regarded as "Peter's successors", in a clear sense.
So it is you who will finally unravel the effects of Aquinas, his own theology upon which the RC long relied, carefully separating out the fact from the well blended fictions? For this is not a simple matter of declaring some documents to be spurious and even fraudulent, but of what effect those same had on developments themselves, which are at this stage nigh unto impossible for a human being to unravel, particularly one who has already decided to just go along and accept whatever official "magesterium" has to say.
If they had already unraveled and nullified the consequences, then there would have been no declaration of infallibility, for such papal decrees as "all must be subject to the Roman Pontiff" and the like, which themselves had relied upon the falsehoods which had been sneaked into the Western church, being as they were originally presented to a pope as being of great antiquity (instead of being chiefly a pack of lies, with just enough truth mixed in to make it seem to all be "true"). That pope handed those to Aquinas (or likely as not, copies of the documents) and the rest as the saying goes, is history.
Do you have a time machine?
Good luck. You will be needing some of that, and more.
I fail to see that “history” shows the popes to be more culpable than their adversaries. The papacy is indeed a Court which like all courts has come into being because of the felt need to resolve disputes. That is one basis for Newman’s notion of development. The papacy came into being because there was a need for it. The bishop of Rome became the bishop of bishops because there was a felt need for it, and it has endured because that need remains. Like Peter’s leadership of the disciples, it happened accidentally. It has endured accidentally. The real question why no alternative has appeared which works so powerfully on events, so persuasively on men’s minds.