Any reason the author insists on spelling it "OS/X" or is this just their personal preference? It shouldn't, but this bugged me when reading the article.
Edit: in fact, most of this is tinfoil hat. I'm all for safety and security but some of this is pretty extreme. "Don't trust third-party Mail providers like Gmail?" Not sure the author realizes a good number of people they're emailing use these services, so should people not converse with Gmail users?
This entire list of suggestions and "explanations" is straight-up FUD.