Digging through ancient texts

The Orthodox and Catholics have all the books from the Septuagint, which is what most of the early Christians would have known regarding the Old Testament. Those "extra" books that Protestants call the Deuterocanonical books (or that the general laypeople often refer to as 'The Apocrypha'), they're just part of the Old Testament the same as the more familiar OT books.

During the Reformation in the 16th century, Luther decided to remove these books (and planned to remove some New Testament books too) as he believed they weren't canonical and cited Jerome as his authority to make this decision. It was Jerome who, in the 5th century, distinguished between the Hebrew and Greek Old Testaments and said (quite controversially in his day) that those not found in the Hebrew version, were not canonical.

Other Christian writings were in some local canons of the New Testament, such as the Didache, the Shepherd of Hermas and writings of Clement, Polycarp, and Ignatius. While they didn't end up being in the canon as we know it today, I think that everyone ought to read them, even if it's just once to see what the early church was reading and saying to each other after the Apostles were gone, or at the end of their era.

And this is what started my 'journey' into the older texts. I knew Catholics had "extra" books, but I never really understood why. I also knew the Reformation had something to do with it. So I began to research and, as stated above, I found that Luther removed some books from the OT and also wanted to remove some NT books as well.

This led me to a question: How, and on whose authority, did Luther just change the Bible? And why was it accepted? 

I know that Luther cited Jerome as an authority (and from what I understand so far about Jerome's reasoning against the Deuterocanonical books, I disagree with his decision), but is that enough to change the accepted canon? Could I, or indeed any Christian, cite another person from church history who opposed Jerome, as an authority to put the books back? Or remove others?

It all just seems like an endless spiral into chaos.

From here I've read many things and have been looking at the formation of the Canon, inspiration if scripture, how these things were decided and what the early church practice was in these matters.
I don't really have a conclusive answer to any of this yet, except that I don't believe that canon is (or should?) ever be completely closed. From my understanding so far, it would appear that the canonical lists were set as guidelines of what had been approved by the wider Church so that Christian communities could know what to use for teaching the basics of The Faith and to also guard against heresies, while at the same time still being "allowed" to use any other books/letters they had which were either unique or popular to that area or community.

I still have plenty more to read and study. At the moment I'm just reading through as many of these old texts as I can. I read the Apocalypse of Peter recently - that'll keep you awake at night! It was accepted at one point, kinda glad it's not now or we'd have some really freaky Hell doctrines (if we don't already). Think Dante's Inferno - this apocalypse was an influence for that!

I am intending to write more about these ancient texts as I go through them and my thoughts, as I journey closer towards understanding how we got to where we are today with the Bible and the Church.