While I see what you are saying, it strikes me as advice that would make him fade into, if not irrelevance, some kind of "Sages of Yesteryear" status. It's safe, but you don't generate good ideas by being safe. (I don't have anything against pseudonyms but they are hard to keep secret.)
Part of the point of writing essays is to explore ideas honestly, and honesty is often not safe. I hope he stays honest.
necessity as they say is the mother of invention. money is the mother of indolence and sloth. hence the essay. The issue about mixed motives is also tied in their somewhere, too. honesty comes more freely to those with nothing to lose. whilst those with everything to lose, have averything to gain from shading the truth. {etc}
Part of the point of writing essays is to explore ideas honestly, and honesty is often not safe. I hope he stays honest.