Well, that is just somewhat silly, as there is no contradiction at all between any of the three Dawkinses (is that plural of Dawkins?). One can very easily be a rational humanist evolutionary biologist.
Yes, but in Dawkins the combination is hilariously incoherent. Barr is a physicist, himself, his review's worth a read.
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Perhaps you could point out the incoherency?
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Does Dawkins even acknowledge "truth"? As I understand it, the scientific method is not a method for arriving at truth, but rather at precise measurement and repeatability--in other words, consenus among professionals, definitely not the same thing as truth.
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Well, having read his work, Dawkins does seem to acknowledge truth. Indeed, he has often said that evolutionary biology is true. In the same sense that it is true that the earth and the sun orbit around a shared centre of mass.
Barr does it quite well, himself. The Devil's Chaplain Confounded.