Good catches on the typos I'll get on fixing those. And thanks for confirming my own suspicion that the shorthand is a bad idea. It's something Aaron Swartz, Dan Schulz and I were playing with before Aaron went off and made the even more cryptic "markdown". I use it for my JavaScript element make routines, but for markup it's just not good. (Sorry Dan, RIP my friend.)

For the header/footer/main thing, that would be true if header/footer/main influenced the use of heading levels, such as the WhatWG's garbage idea of every section being reset to H1 depth. Problem is that's too confusing and complex for most screen readers or braille readers to deal with, which is why before we had those tags you'd use an HR though it wasn't 100% navigable. Footer acts neither as a landing nor as a grammatical element, and that's really what's wrong with it.

There needs to be a tag equivalent to numbered headings for such "easy landing" implementations. Either that or we use the existing numbered headings and hide them on visual UA's. I've been mulling that over in my head with the idea that maybe an attribute to hide a numbered heading for visual UA's might be more appropriate.