FAA Regulation

Civil and public aircraft operations. Public and military operations. Civil operations. 

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

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

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, ...

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.

Not compliant with Part 107. Part 107 does not apply to this scenario. Compliant with Part 107. 

November 28th. November 11th.  October 28th.