FAA Regulation

must not cause injury equivalent to 25 foot-pounds of kinetic energy upon impact. be operated in accordance with the operating limitations specified in the approved Flight Manual. be 0.55 pounds or ...

They can maintain line of sight and without loss of control.  They briefed each other before the flight. They are in radio contact the entire time.

receive type certification under Part 21. have remote ID for all operations over human beings. be operated by a Part 61 pilot.

Without the possibility of direct human intervention from within or on the aircraft.  For hobby and recreational use when not certificated. During search and rescue operations other than public.

does not contain any exposed rotating parts that would lacerate human skins upon impact. has an airworthiness certificate issued under Part 21.  is labeled as Category 4.

The owner of the aircraft. The manufacturer of the aircraft. The operator of the aircraft.

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

Denial of an application for a period of up to 1 year or suspension/revocation of a remote pilot certificate.   Up to 1 year in jail. A fine up to $10,000.

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

Only when visual observers participate in the operation. Alone, if operating during daylight hours. Under the direct supervision of a Remote PIC.