I do take many of your points, I find them perfectly logical, but still I basically agree with A...64 and Fredrik.
I think Dawkins, in particular should debate with creationists - in part because I think he puts himself into that arena. Moreover, I am far from sure that the issue here is ultimately one of logic. As Dawkins himself says, the human psyche seems to have a God shaped hole in it, which implies that, even if it is not logical, much of this debate is perfectly sincere. In these circumstances, I find it inappropriate for a professor of the public undertanding of science to present himself as intolerant of dissent, which he seems to. (Even people with a God shaped hole in their psyches are members of the public.)
You're making a good case for Dawkins to step up, because I've always maintained that if you stick your head above the parapet, expect it to be shot at, and Dawkins likes to stretch his neck more than most.
But...
Also, the question remains about whether the same debating tactics are applied within other fields of science and whether this sort of exclusionary approach is used to suppress real debate about real scientific points at issue. The matter of Sloan Wilson and group selection then becomes rather apposite in respect of Dawkins.
Haha! I smell a secret agenda!
Group selection, as far as I can tell, isn't suggesting that all of science is wrong. Right or wrong, it's one hypothesis among many in evolutionary science, but it's actual science, not a fairy story. Creationism requires suspension of science.
Consider it from your own point of view. A nationally-televised debate between you and Dawkins would give you great credibility, no matter whether you were perceived to have "won" or "lost". It may not confer scientific credibility, but creationists don't want science's approval, they want new blood for their tithing plates. To a fundy, seeing Dawkins even debating the issue is as good as a win - it's moved his argument from the realms of idiocy into a subject debated by [arguably] the most famous scientist on the planet.
Debating against them is an automatic win for their team. That old, old saying; any publicity's good publicity...
While refusing to debate fundies isn't a good look for Dawkins - as you said above, don't knock it if you can't stand up to debate on it - the alternative is to hand the fundies an easy victory. I think the lesson learned might be that Dawkins should stick to evidence and not offer so much opinion.
All the reasons not to debate creationist are valid enough. I wonder if a message board debate where the debaters where by invitation only would work. The debate would still be turn based and moderated. Any post that the mods rejected would be made public. Would any here consider it possible to define a protocol that would make such a forum useful?
They run a good debating system at IIDB, where rules are established beforehand.