A lot of ideas I like apparently didn't get in.
Rioting is an example of an idea that didn't make the cut apparently. Mass panic and people fleeing should definitely be considered as aspects.
Another interesting concept is having it mutate differently in different areas. But then, that would destroy the premise of it being a single conscious mass organism as opposed to a species of separate organisms.
And of course, certain other factors, like if suddenly three billion people are stricken with insanity, the repurcussions would be unimaginable. Perhaps certain effects should take place if, say, a certain percentage of the populace has that condition? Insanity being the example, if 30% of a country is insane, there would be no way that any of the country's lockdowns or curfews would work.
I know it takes a long time to program all these lines of code, and so implementing all this stuff is probably all the more difficult, but I think you've got a good thing going and that any effort put into additional factors, scenarios, and options will be well-rewarded with satisfying gameplay.