Thank you for your response. First of all, while I think the OTF, used as a heuristic, can help us try to escape our biases, I have serious doubts, based on my training in epistemology, that real, genuine, freedom from bias is really possible. In the real world, we have to chip away at our biases, as opposed to performing some miraculous operation that will eliminate them entirely. As Steven Jay Gould once said, "We don't know what our biases are, because if we did, we'd eliminate them." Interesting enough, in the Christian Delusion Loftus emphasizes all the sources of bias that we fall prey to, which suggests to me that we aren't going to achieve intellectual liberation with one simple test, or just by "being careful." Intellectual sainthood is about as rare as moral sainthood, as I see it. And, I really don't believe in the existence of "neutral ground."
Second, there may have been passages in the site which I referenced which indicate a Christian bias. Unfortunately, the link to the page is now broken, so I couldn't check the passages to see if, in full context, your reading of them was correct.
But, even if they fell into question-begging at certain points doesn't mean that the central argument of the site begs the question. The site, as I saw it, was primarily concerned with comparing the manuscript evidence, the documentary evidence, and the archaeological evidence for the Bible and the Qur'an. Suppose they had stuck to just those comparisons. It looks to me as if those comparisons can be made, and that, in fact, the Bible does come out better if you compare on those grounds. I don't expect any investigator to be perfectly unbiased, but this site did set of a format which, if they stuck to the format, would show a legitimate difference between the Bible and the Qur'an. Thus, so far as I can see, evidence does exist that gives us better reason to believe that the Bible is revelatory than to believe that believe that the Qur'an is. So at least some of their content falls into neither category that Loftus mentioned: either assuming methodological naturalism on the one hand, or assuming the truth of the Bible on the other. And my claim is that it looks perfectly possible to find reasons to believe in Christianity that one cannot find for Islam.