I agree. From experience, shooting a handgun accurately at a target more than 25yds requires both training, competency, and fine motor skills. Doing the same with moving targets, even more so. Even if sober, this is NOT an easy task, without extensive training and practice. If GW was under the influence of alcohol, IMO there would have been significantly fewer lives lost.
This leads to one of my (many) unanswered questions... If presented only with the body count and the lack of injured people, a logical conclusion is that the killer had extensive training. So, where did GW learn, train, practice handgun shooting, and with whom? Without his PAL license, it would not have been at an established range. There is a huge missing piece to this puzzle and I am certain that the RCMP investigation is actively pursuing the answer to this question also.