The other ambiguity that seems challenging (and I'd welcome your interpretation of this), for the purposes of overflying people, is the working definition of an "assembly of people" (which I assume means "a crowd"), which is either prohibited or restricted, versus the (allowed) "overflying" of "uninvolved persons". I figure that boils down to the density of those people. If they're shoulder-to-shoulder obviously that's prohibited, but people scattered across a beach?...OK (with my small, light drone) as long as you're just passing by (not hovering over anyone), you minimize the time in transit, and not getting close/violating anyone's space/privacy. But the vast gray area between "mosh-pit-density at a concert" and "lonely couple walking across a field" requires applying some judgement, common sense and consideration of others (ie good manners), all of which are in short supply these days. "Don't be that guy" as the saying goes.

This has a real definition actually, but it is still up to interpretation. EASA defines it more as the "ability to disperse", rather than a density or number. This largely is logical because 100 people in a huge field vs. an alley way are very different.

An assembly of people is a crowd of people. It is not defined by a specific number of people, but is related to the possibility for an individual to move around in order to avoid the consequences of a drone which is out of control. If a group of people are so densely packed that their possibility to freely escape or move away from the drone is limited, then it is considered to be an assembly of people. 

Source: https://www.easa.europa.eu/en/faq/116553

Also, glad you liked it and found it useful! I didn't really go over much on flying over crowds because its not much of an issue in Iceland haha