"What is your opinion of the Coptics, the Gnostics, and the lost sea scrolls, in relation to the assertion that the bible has never been tampered with or edited by man?"
Thanks for your long, thoughtful post. We seem to have taken similar paths, with somewhat different results.
As for your questions about writings not in the Canon of the New Testament, I really don't have any answers, except to point out that at the time the Canon was set, it's valuable to examine the political and social landscape of that time.
Decisions were made to include and exclude writings. If you examine some of the material that wasn't included, it's often easy to see why it was not. Further, since new writings from the period of the early church have appeared, long after the canon was set, those are also interesting to examine.
It's a credit to the power of faith that so much exists from those early days. The current canon is an assembly of such documents, along with some oral tradition, no doubt, but is not necessarily based on accurate material.
Nothing in the current New Testament was written by any contemporary of Jesus. Indeed, we don't even know the original authors of most of the New Testament. Paul's letters, perhaps, represent the most authentic of the writings included. The gospels have always seemed like an assembly from fragments to me. Where they have things in common, they probably come closest to providing Jesus' words.
Christians accept the New Testament as accurate on faith. I'm not as willing to do so, and continue to study all the available documents from the early days. Some have very different viewpoints from the Canon.
It's all fascinating.
"Paul's letters, perhaps, represent the most authentic of the writings included."
Paul is my favorite. What an incredible man with such spiritual power and strong personality. If not for him, I don't think Jesus would be very well known today.