I’m a copy editor, and a proudly curmudgeonly one at that, so I suffer the same kind of annoyance at the kinds of mistakes you’ve targeted here. When I complain about it, though (and I rarely do with online stuff like this, unless it’s something egregious, or I’m familiar with the author and just want to needle him or her a bit), I make damn sure not to have errors in my comment. No competent editor would countenance the “she/he” construction you’ve used (it should be “she or he”), nor the number disagreement you’ve committed with “the person…their tweet….” 

1) You are correct, one improper “its”  (out of 9) escaped me. You are ruthless!

2) Thank you for finding a word not in my spell check’s dictionary. Spelling errors are hideous, I agree. They invalidate anything any everything we right (sic). I will always be in your debt.

3) If after reading this document, you still cannot grasp the utility of a code that millions are now using because they do, I cannot help you. I suspect no one can.