Incorrect:

  /*
   * 1. Corrects text resizing oddly in IE 6/7 when body `font-size` is set using    
   *    `em` units.    
   * 2. Prevents iOS text size adjust after orientation change, without disabling    
   *    user zoom.    
   */

  html {    
      font-size: 100%; /* 1 */    
      -webkit-text-size-adjust: 100%; /* 2 */    
      -ms-text-size-adjust: 100%; /* 2 */    
  }

Your statement would be true if it was setting -webkit-text-size-adjust:none, but 100% does as the comment says and only prevents resizing when changing orientations.

Did you test this? On my iPhone (iOS 5.1.1), the above css snippet disabled automatic text size adjustment.

If you have an iPhone, look at my test pages to see for yourself:

http://jabakobob.net/2012/08/hntest/test.html (without snippet)

http://jabakobob.net/2012/08/hntest/test2.html (with snippet)

For me, the first page renders with a much more legible text size.

> this file disables the webkit text size adjustment on the iPhone.

No it doesn't.

Yes it does. See above.