Referring to your #4:
I once found a book ripped from its binding, as well as loss of quite a few of its printed pages. It was immediately apparent to me, because I am more than a little familiar with the subject, that it was a cookbook; a book of recipes of meals; grilling, as it happened. I am an accomplished cook and use this medium quite often. So, reading through the recipes, I found one for grilling salmon fillet that, while the salmon was thus on the grill, offered time to make an apple brandy cream sauce. The two elements of the main course were prepared so that each was done at the same time, and turned out to be an excellent meal, worthy of fine restaurant production.
What should I conclude? I had no book title, no publishing information, not even the author's name in order to find the entire book, because this one recipe confirmed to me the author knew their stuff and had delicious recipes. I made quite a few of the other dishes offered in what I had of the book. Do I conclude the book is "fake" because I lack the information I mentioned. No, I don't, because the recipe told a true story of a delicious meal.
Is that is the sense of other types of information, such as contained in the Holy Bible? Is that volume a complete volume? Several centuries ago, some alleged experts in the subject picked and chose from volumes had, and created a "canon" that is not all that was available to be had. Did God decide which books to include? Maybe; maybe not, by inspiration, but it is what it is. So, what do we do with it? How about the same thing as my incomplete cookbook: try it. Apply the principles in it and see if they result in being in a good place for body and soul.
You get the point. It is not going to declare its true value by sitting on the shelf and our doing nothing about it, making claims of either its authenticity, or its worthlessness. You seem to be willing to take that worthless approach, but not all of us agree with you. Better yet, some of us have applied the principles contained in what may be an incomplete book, and they prove their worth, just as my salmon with apple brandy cream sauce.