This is a very well written piece with lots of good advice. Thanks a lot for writing this.
It may contain some interesting points, but it is obviously written by an ESL writer.
I find it fun when native speaker complain about ESL speakers, since in the end it is likely that international English will win.
I live in a non-English speaking country, the common language in the office is international English (there are 60+ nationalities, and less than 20% are native english speaker). It would be fun to track over time if the native speakers start speaking international english :)