Very nice stuff above. The main theme, as i think, is the quads need to be significantly commanded to be kept out of the way of full scale airplanes.
Now that is the same problem that is big time around the Highways and even lesser roads. Every day the highways and roads are down because of dumb-butted people driving at break-neck speeds and damage from fender-benders to ultra bad wrecks with multiple deaths. Personally I despise speeders, text-messaging while driving, and drinking alcohol drinks before and during driving. It will happen. So what is the answer? IMO, not just a "fine" but a minimum of 6 months in the slammer!
My bet is that there are 1000% more quad fliers than AMA RCers. How can it be controlled? No Frigging idea, except that learned RC fliers should be aware of those problems and do their best to assist anyone doing the wrong things to give significant thought to what danger they could develop especially in the vicinity of full scale.

Explaining the difference between knowing and not knowing or not caring can be helpful to those that do care but do not know. One of my days was returning to Laredo AFB after a 3 day cross country. Decided to stop at Randolph AFB (San Antonio) for some lunch and fuel. VFR approach, on the downwind leg (1500 ft. above ground), BOOM, airplane into a heavy shudder, EGT went to max, declared emergency, shut the 0ne & only engine down (T-33) rolled into a steep bank and a dive turning to runway end, had enough hydraulic pressure to drop the gear and some flaps down, then rolled out on a short final and landed. Got towed into the maintenance area. There were several holes in the airplane from the turbine blades behind the OLD Centrifugal Flow engine. The CF Compressor stood a lot of hard use. OTOH the turbine could sling a few blades now and then. When anyone becomes a "Book of Knowledge" ref. the actions of a jet engine, my bet is there will be a few surprises just waiting.
Knowledge is the main thing, but you ain't gonna' find it in the Hobby World other than those that do it frequently and WISH to remain safe.