I read this article in NY magazine, on the coronavirus lab-leak hypothesis. I found it fairly convincing, so I think the chance that SARS-CoV-2 passed through some human laboratory before spreading to people is better than not. But when I tried following up by reading other sources, I found myself falling into the trap of trying to just confirm my existing belief. How might we estimate a probability that SARS-CoV-2 passed through a human laboratory at some point before spreading to humans?
I mean to include all the alternatives that involve the virus passing through a laboratory before spreading to humans; so all the options you list are included. There's nothing wrong with asking about the probability of a composite event.