This makes sense if the disease propagates linearly like bacteria on a petri dish. But it probably doesn't. It may spread more like a wildfire -- there can be burning branches blown miles from the main fire that only smolder or set a small patch of grass burning which flames out due to lack of fuel. Meanwhile the main fire is only stopped by water or other major geographic feature.

I could see it as possible. The spread is asymmetric. You could have one infected person who is not a super spreader only infect a few other people who just happen to be asymptomatic and not spread it to others. When your overall infected population is very small, like in the beginning of a jump from animals to humans, then you have a chance to get lucky in this way. Once you get to a larger infected population (like dozens of people) then you're more likely to have a super spreader and less likely to get lucky with only contacting asymptomatic people.

There are back-confirmed cases of covid in Italy in September 2019, so the Wuhan incident is definitely not a patient-0 situation (even if it could be a ground-0 location from previous patient-0 situation, but its just a guess and we'll never know).

Given that, having a case in Beijing in November 2019 is entirely plausible

Yes I remember a friend who lives in Hong Kong posting a news article (from a Chinese news source) describing a "mystery pneumonia" the first or second week of December 2019. He hypothesized that it was because of bushmeat. I think the news article got scrubbed. I wish I had saved it.