My excellent philosophy professor summed it up rather succinctly: there are two types of arguments, arguments with a goal of synthesis, and arguments with a goal of victory.

I haven't read that book (and now will), but I would also recommend another classic, Fritjof Capra's Web of Life

Generally speaking, according to Gaia theory, the earth is one system, functioning simultaneously at all levels of scale. Those levels are only artificially segmented according to the biases of an observer, and are not atomic but a continuum, with all levels equally interdependent upon and interactive with all other levels. Soil bacteria speeds rock weathering, the chalk shells from dead oceanic algae lie on the sea floor and affect geothermal activity, etc. "We can no longer think of rocks, animals, and plants as being separate. Gaia theory shows us that there is a tight interlocking between the planet's living parts ... and its non-living parts ..." (p104)

So yes, once one has wrapped their head around this concept, it's no surprise that all living systems are interconnected as well, especially those so tightly coupled as to be considered classically symbiotic. We are not just their environment, they are ours, and we share causation.

From the article:
"...changes in the acoustic emission with time are a sure indicator of changes in the physiological status of the peripheral auditory system. This property has been used as a sensitive indicator of changes caused by noise or therapy on a patient's ear."

So this method is sensitive to normal physiological changes within the inner ear. If I just came from a concert, can I still check my bank balance by phone? What if I spent a week at the lake? What if some lint from my pocket has found its way into my cell phone? Too many defeat scenarios for this to ever be a primary identifier.

Working in a web shop where lunch conversation was occasionally about how thoroughly we had memorized the hotkeys for our favorite dev programs, I hacked up some foot pedals for one of our designers by destroying a usb keyboard and wiring directly into the keyboard's controller chip. What we eventually found was that the average desk worker does not maintain the same posture all day long, but instead alters it, shifting weight to the left, right, or center to alleviate fatigue. This made any particular arrangement of foot pedals uncomfortable to use throughout the course of the day because it required maintaining a specific posture or rearranging the pedals at every (previously unconscious) shift in the chair. Now, we did not have $1000 chairs, so perhaps foot pedals could work with some highly ergonomic office equipment, but our relatively simple setup didn't afford further testing.

As to what difference is made by rearranging the letters on the keyboard, I believe that the primary argument should not be about speed but efficiency. Most people type only in short bursts anyway, so wpm is a diminishing return metric above a certain threshold (I've heard around 35), but highly efficient layouts dramatically reduce the finger and wrist work required to type the same text, which reduces fatigue and injury. I suggest checking out http://klausler.com/evolved.html for an example of unbiased methodology which shows that Dvorak reduces effort per text by over 50%, which I may add, has been my experience. I switched to Dvorak after I started noticing early signs of CTS (numbness, tingling, etc) and have had 0 problems since, 6 years later.