FAA Regulation

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

If prior permission is received from the Federal Aviation Administration. If precautions are taken to avoid injury or damage to persons or property on the surface.  Only in an emergency.

visual observer. remote pilot-in-command.  owner of the small UAS.

Continue the mission, airplanes are not allowed to fly lower than 500 feet AGL unless around an airport. Give way and stay clear from the crop duster.   Continue the mission, ...

30 days. 10 days.  90 days.

No more than three as long as the Remote PIC maintains visual line of sight. As many as he/she can handle. No more than one. 

is required to receive ATC authorization.  must use a visual observer. is required to file a flight plan.

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

Remote Pilot in Command. Commercial Balloon pilot. Designated Pilot Examiner.

Over suburban areas. Over a parade or other social events. Over a sparsely populated area.