My bible inerrancy challenge to Rational Christian Discernment

A blog called Rational Christian Discernment puts forth a lot of effort to trifle about atheist scholar Bart Ehrman's alleged "errors" concerning the doctrine of biblical inerrancy.  It does this with an article to that effect written by Dr. Peter J. Williams is the Warden, (CEO) of Tyndale House and a member of the Faculty of Divinity in the University of Cambridge. See here.  The blogger apparently cross-posted that article from the inerrancy-fanatic "Triablogue" blog site. See here.

I posted a direct challenge to biblical inerrancy in response to that article.  However, the resulting screen said the post would be visible "after approval".  So there is a risk here that I've endured for years...that my challenge will simply be quietly deleted by the zealous inerrantist in the hopes that it will just go away and allow them to forget about it.

But...I have declared war on all things Christian fundamentalist and Christian "neo-fundamentalist".  If you don't answer the polite knock at your door, it will be kicked in.  You will either admit your dogmatic certitude is nothing but hot air, or you will endure challenge from an above-average bible skeptic.

So to protect my reputation, preserve the challenge and make sure God's fearless warriors for inerrancy are forced into the debate arena, I've cross-posted that challenge here:

I'd like to discuss with you the following argument I have created to refute the doctrine of biblical inerrancy: 

Several inerrantist Christian scholars, along with other conservative but non-inerrantist Christian scholars, all of whom accept Markan priority, assert that Matthew and Luke often "tone down" Mark's expressions or otherwise omit them altogther.   

Why would it be the least bit "unreasonable" for an atheist or bible skeptic to infer from these scholarly admissions that Matthew and Luke likely didn't think Mark's gospel was inerrant?
Have you ever met any inerrantist who put forth effort to "tone down" or "omit" any biblical wording that they believed to be present in the autographs?   To believe in inerrancy is to positively and absolutely preclude any desire to "tone down" or "omit" any of the bible's original words. 

"maybe they were working from an errant copy of Mark" is nothing but a possibility, whereas historiography is an art not a science and proceeds by degrees of probability.  Nobody can win such a debate merely by conjuring up a "possibility".  So if you invoke this particular possibility, I'd like to see the historical and biblical evidence in favor or it, and why you think that "working from an imperfect copy of Mark" conclusion is more reasonable than the "they didn't think Mark's original was inerrant".   

The inerrantist scholars who believe in Markan priority are always saying, without qualification, that "Matthew tones down Mark here", as if they wanted the reader to believe Matthew was toning down something Mark himself wrote, not merely toning down a textual corruption within a copy of Mark.I