1. Why is the drone operator following this particular person, what is the purpose of his mission?
The drone is clearly focused on the the vehicles, zooming in and out on them, and the bicyclist is in the lower right corner most of the time. Only after the shot did the camera zoom in on that location.
The rest of your bullshit is equally absurd. There is plenty of evidence of Russian forces shooting civilians for spurious reasons or no reasons, as well as robbing, looting, etc. "No motive"

For example:
https://www.bbc.com/russian/features-60988371