Agreed, motos need to pass riders and in doing so will be closer than 100 feet, but they won't be directly behind the rider(s) while passing, so should be less likely to hit a fallen rider. I'm thinking that there needs to be a minimum following distance. And a minimum leading distance, for draft reasons. And when passing, a minimum passing separation (this would be more like a few feet) and maximum speed delta (10-15 mph?).

For all I know, maybe there already are such rules. If so, they must not be enforced. While watching the races, you see motos blasting by riders, only a couple feet away, all the time. Riders hemmed in by a wall of motos. Motos following only a couple bike lengths behind riders. Routinely.

I'm interested in drone video cameras, but not so much for safety reasons. The TV motos are seldom involved in accidents, at least I can't think of any.

To have a long enough flying time, I wonder if the drone needs to have wings rather than being purely a 'copter. And perhaps it needs to be gas powered. Then the question might be, how slowly can a winged drone fly.