While your reasoning is byzantine, and beautiful in its own way, I think you're working too hard on it. You claim that even if the U.S. and the other members of the Security Council were convinced about WMD at least up to 2002, that Bush had to lie or misinterpret data to arrive at exactly the same conclusion as everyone else. Naturally, unless that data changed drastically between 2002 and the invasion, this would mean everyone else lied or misinterpreted the data.

You do realize that a much less complex answer that explains all the facts is that the data was read properly, there were in fact WMD as described by Bush, Powell, Blair, the United Nations, and others, and that they simply haven't been accounted for yet. Given the time he had before the attack, Saddam would have had no trouble hiding whatever evidence he needed to. Remember, these systems were designed with concealment in mind in the first place.

(I personally think the "Emperor's New Weapons" theory, where Saddam was hosed by his own people, answers a lot of puzzling questions. But there is, as far as I know, no hard evidence at all for this.)

And of course, evidence that we have actually found, like the biowarfare trailers, has been lamely dismissed as hydrogen plants for balloons. Never mind that they don't look anything like similar systems built by anyone else, or that none of the naysayers has gone to the trouble of asking Marconi for the specs for their artillery balloon system, which would settle this once and for all.

As to why hydrogen gas plants were carefully hidden and buried by the Iraqis--obviously they buried them so we wouldn't find out they were manufacturing hydrogen, a known component of fusion bombs.