I also take Jesus myth theory pretty seriously. When I've investigated this matter, it has always seemed to me that the evidence that Jesus did not exist is fairly weak, but the evidence that Jesus did exist is even weaker. I whole-heartedly concur with your assessment of the unsoundness of Jesus Studies. To make one highly relevant point, I do get the impression that mainstream historians have largely absorbed the point that extravagant legends are not always based on a kernel of truth; plenty of them seem to be entirely invented (or at least their inspiration was so different from the final story that the final story doesn't even provide helpful clues to anything any more). This point does not seem to have penetrated most discussions of Jesus. Does Carrier's invocation of Bayes add much to what previous proponents of Jesus myth theory (I'm most familiar with Wells) have had to offer?