The word "reasons" would have been syntactically far, far better.

Also, you can't use "little" with "documents" - "few" is correct. And I guess relative to the explosion of information that we have for the past two hundred years or so, we do have few documents that are 1600 years old. But relatively speaking, we have quite a lot. In fact, there has been so much information coming out of Egypt that often these papyri were used for kindling prior to, say, 1950. That's what almost happened to the Nag Hammadi codices. Scraps of papyrus this small are common finds in Egypt, and usually they're not significant.

By pointing out that it would have "more religious authority weight" (again, couldn't you say it would be more authoritative? what's with your syntax in this response?) if it were not 300 years after the start of the Christian era, you undermine your argument, because my exact point is that it isn't authoritative because by that point in time, there were dozens of Gnostic groups operating in Egypt, and several talked openly about Jesus being married to Mary Magdalene. Dan Brown correctly cited one of their surviving papyri (though of course he then threw on layer upon layer of fictional shit on top, and served the whole steaming pile of crap to readers as the "truth", when in fact it wasn't).

Your second point undermines your argument even more than your first, however. You point out (correctly) that most people don't know much about Christian history. If that is the case, this fragment will be even more misleading to them, because as we all know, a little bit of knowledge is a dangerous thing. They will conclude (if they hear about this) that Jesus was married, that Dan Brown was right, that there is a Templar group keeping His descendants alive, and so on in that manner.