I'm with you Kid, A all the way. What the heck is UAS 400???? It's rules and regs regulating models. In part it separates professional modelers and professional RC pilots, from hobbyists. Every sentence in that 12 page document is a rule, policy or provision on RC aircraft a.k.a. models, for both professional and non-professional RC pilots.

What the FAA doesn't regulate is non commercial (no job too small) RC activity a.k.a. hobbyists. And of course they only regulate hobbyists up until the point you want to find out whether or not AC 91-57 is just a "memo" or perhaps something a little more kick to it, especially when it's limits are surpassed.

A field designated for RC operations. And yes, that matters. I don't think the AMA wants to worry or not whether you'll be performing your commercial airshows in areas designated for RC flight, or a carnival parking lot. Thus the policy for paid instructors.