FAA Regulation

The National Transportation Safety Board. Upon request of the Federal Aviation Administration.  Air Traffic Control.

must not cause injury to a human being equivalent to 11 ft-lb of kinetic energy.  must have an approved type certificate issued under Part 21. must not cause injury to a ...

Person manipulating the controls.  Visual observer. Remote Pilot in Command (Remote PIC).

No, the other people in the park are not on notice.  Yes, as long as the park is not busy enough that it would be considered an open-air assembly of human beings.

Quadcopter capturing aerial imagery for crop monitoring. UAS used for motion picture filming. Model aircraft for hobby use. 

make sure the UAS is within 400 feet of the control station. maintain line of sight throughout the entire process.   have a visual observer.

Yes, it will cost $5 per aircraft. They don’t need to, your aircraft are already registered and your pilots are certificated. No, they will have to obtain operating authority from the Department of Transportation.

No Medical Certificates are required. A Class 3 Medical Certificate A Class 2 Medical Certificate.