That Would Have Been Great In Theory...
1) The quintupling of arms inspectors wasn't just a matter of waving a wand. They needed to be qualified, and what countries volunteered to offer their services in the amount you suggest?
2) If you're quintupling what makes that justified over and increase of say ten-fold? Who pulled a multiplication factor of 5 out of thin air?
3) The issue wasn't the number of arms inspectors, it was a matter of open cooperation by the Iraqis with those arms inspectors. We had already increased the numbers of inspectors, but it did no good because the cooperation didn't exist, like it with with S. Africa years earlier. With full compliance we probably needed a handful of them. No, without full compliance it made no difference against hundreds of thousands of people who could be instrumental in conducting a never ending shell game in a country the size of California.
4) The invasion of Iraq was initially about WMD and Saddam's danger to it's neighbors and us, via the transmission of WMD to terrorist groups that he had (well documented) connections with, and his propensity for having his troops rob and rape Kuwait, and attempt to do so against Iran years prior.
5) The invasion was also about changing a regime which may have been responsible for millions of deaths to it's own citizens. Hundreds of thousands are known at the very least. Note: 270 mass graves have been discovered to date. The long list of human rights violations makes China look like a preschool. We don't need to list them.
6) As it turns out our troops in Iraq are attracting many of the very terrorists which have not found a way to successfully attack CONUS (cont. U.S.) since 9/11. Essentially they, along with innocent Iraqis are taking hits for us, in exchange for providing that country with a chance at a free society, and along with that all the ramifications that go along with such an endeavor. The success of which would have an incredible impact towards world peace many years down the road, in mine and many other's opinions.
7) I respect your position that we should finish what we started and I really wish we could hear more of that from democrats as well, at least. I had no problem respecting the argument not to go in the first place, but that time has passed.