If you want a text that seems spurious, how about this? "…go to the sea and cast a hook; take the first fish that comes up, and when you open its mouth you will find a coin; take that and give it to them for you and me.” Matthew 17: 24-27, on paying the temple tax.

That doesn't bother me, like the adulteress story not being in various MSs. While the coin story seems fishy, the latter rings true, Furthermore, Jesus is also pointing out to the men that the law requires both partners to be stoned, not the woman alone. In other words, they are sinning against the law as well.

Beyond that pericope, some think the Prologue ("in the beginning") is an addition, Chapter 21 is certainly tacked on, and it ends with "there are also many other things that Jesus did; if every one of them were written down, I suppose that the world itself could not contain the books that would be written.' John 21: 25.

None of your arguments are substantive.

And no, stoning is not acceptable to Christians.