To be frank I dont understand what you are trying to say regarding not using Aperture mode on the M9...
I do believe you misunderstood. Thorsten DOES use the "Aperture" mode, but he DOES NOT ADJUST the aperture. His style is to keep the lens at full open aperture, choose the ISO, then let the camera choose the shutter speed. Thus, one could consider that A stands for "Automatic" as it automatic shutter speed. Just a semantic argument. The take home message is: set ISO, open the lens wide, set shutter speed to "A", then just focus and shoot. Or, to put it another way, always shoot at full wide aperture and let the camera pick the shutter speed. I find this a fascinating take on how to use Leica lenses; it may not suit everyone.
I do find the WB advice compelling. I continue to have a devil of a time getting the skin tones right.
"The important thing is that when the Leica M9 is once set to Manual, it's easy to change. Whenever I enter a café or some other light, I pull out my WhiBal and press the Set button twice, expose the WhiBal and I have changed the white balance. If the camera is set to Auto white balance, you have to press Set, scroll, Set and shoot. It's a longer process than changing from one manual to another manual."
Thanks, Thorsten, for sharing your approach to Leica. It is an interesting read.