Great article, as always, my friend.
I will just add to, and semi-counter two points.
SPELLING. Like I tell my students, you don't actually have to know HOW to spell, just how to look for errors, and more importantly, how to look things up when you're not sure. My kids love to give me a hard time for always having a dictionary with me when I write anything, be it an assignment, a hand-out, or a letter home. And I tell them, "It doesn't matter if I know how to spell the word before I write it, just so long as it's spelled correctly after I'm finished."
GRAMMAR. Grammar is a pet peeve of mine. Did you know grammar was never intended to be taught? What we think of today as "GRAMMAR RULES" were actually just the machinations of a group of linguists who were simply trying to study the growth and changes of language, not set up the rules for language. The only reason we learn grammar at all is for bureaucratic reasons. Politicians and legislatures wanted something that could be "measured" in the teaching of language, which, is a highly abstract art/science. That's why so many grammatical "rules" contradict themselves and/or each other. They aren't really rules at all, but a means to measure the growth of language.
The irony is, by using grammar as a rule, we actually prevent the very growth grammar was set up to measure.
That said, I understand the need to get your point across clearly and intelligently.
I just figured I would point out that language is always changing, and what we think of as correct today, is in fact, the error of yesterday, and so on and so forth.
...and knowing is half the battle. Yo, Joe!!