Not a bad assumption. Seems fairly logical. Where I disagree is your comment that there is little to support the Admin honestly believed Saddam posed a serious WMD threat.
I'll even amend THAT to say the PREVIOUS administration since I retired before Bush took office. In 98, the SecDef approved them sticking us with anthrax shots. I can't say for a fact that policy was continued past 2000, but I'm quite sure that sticking all deploying Marine and Navy personnel, and the cost involved was not cheap, and not without reason.
I also don't believe the invasion was to stop France's under the table deals with Saddam for oil.
I suppose it depends a lot on what you consider a WMD. Your example of Anthrax for instance is out of context. While it could conceivably be considered a WMD, it is not something which Iraq or terrorists could really use as such against the USA. Like many agents, it is only a WMD when it can be delivered in rather massive quantities, which Iraq and/or Islamic terrorists lack the capacity to achieve. It could certainly be used as a weapon of terror, but the level of effect would be rather limited, probably only a few hundred casualties, quite probably less. I do not think your example of immunizing the military against Anthrax is valid because this was intended to protect them against Anthrax used by Saddam to defend his regime, not in an attack on ours.
So lets look at the Iraqi "WMD" agents:
Sarin: The first on the list is probably Sarin gas. This is a very nasty nerve agent which we foolishly helped Saddam develop in the 80's. Fortunately for us, the Iraqi's were unable to achieve the required purity for the precursors, so what they produced had a very short shelf life. Sarin has a short shelf life to start with and the Iraqi sarin gas project was only able to achieve shelf lives of a few months and in many cases only a few weeks. Even the precursors were subject to short shelf lives. So for Iraq to use this weapon it had to manufacture it when they were ready to deploy it, and there is clearly no evidence to indicate this was happening any time in the relevant time period. The massive expense of the Iraqi sarin project in the late 80's, resulting in the need to dispose of perhaps as much as 40 tons of the stuff at the end of that decade, and the exposure of production facilities to easy destruction by our military, discouraged Saddam from pursuing sarin as a viable weapon for use against the USA. And for terrorists it was simply impossible, except perhaps in minute quantities.
Tabun: This agent, like Antrhax, is a legitimately considered a WMD only when coupled with a large scale delivery mechanism, such as bomber aircraft or Artillery. Since Iraq did not have the capability to deliver it in significance to the USA, this is not a WMD in the context of being a threat to us. And like sarin the shelf life of this agent was a real problem for Iraqi technology.
VX: This is a legitimate WMD in any context. However, there is absolutely no evidence that Iraq had the capability to produce VX. It is believed Saddam may have used a small amount of this weapon against the Iranians and/or the Kurds but even this is unproven, and if he did it would have originated from a Western Country (i.e., the USA or Britain). VX is fortunately beyond the technology of most of our enemies.
Nuclear Weapons: Well, I don't think I have to go much into this one. Clearly an atom bomb is a WMD by any definition. Just as clearly, Saddam was no where near having one despite the Administration's claims to the contrary during the run up to the war. Even had all the evidence presented been true Iraq would still have been at least a decade away from producing its first testable weapon.
So to clarify the issue Gunny, in the context of this discussion we do mean WMD's which could actually be used against the USA proper to effect massive casualties right? Clearly the Administration was not claiming that the reason we needed to take out Saddam was because he had WMD's which he might use against our troops should we invade Iraq.