There are lots of "you need this..." comments, but I'm wondering what is required, legally, by the FAA? A Commercial Rating, of course. Flying for money and all. A Taildragger Endorsement because the plane will probably be a TD. A High Perf Endorsement because the plane will have over 300hp and very likely electric flaps - but maybe not cowl flaps. But the FAA doesn't care about Insurance, does it? And really it doesn't care about the chemicals either, does it? I mean in their statutes. The Chems have state and fed guidelines, of course, but beyond the purview of the FAA. Are there other ratings or certifications involved under the FAA?