1) Rule 5, chosen because I've heard it before and already try to implement it; Rule 6, chosen because there are too many edge cases for it to work well; Rule 10, because Beyond Burgers; Rule 35, because I have good memories of eating things I've found (and a friend more versed in these things has identified) on hikes; and Rule 59, because I'm currently in isolation.
2) I learned how much effort eating healthily would take, and how unhealthily I eat.
3) The author says that he isn't "ready to let [nutritional scientists] operate on [him]" yet, by which he appears to mean that they can't fully be trusted. While I do believe that nobody in the world can be fully trusted, I feel that he doesn't give them enough credit.
And Rule 61 has a typo.