Rainbows, good evening, again.
Black mould is a sure indication of dampness / a wet building fabric, it does not "emit" spores, however living in a "Damp" environment for a protracted period is definitely bad for ones health, dampness can release chemical normally contained in the fabric of the building, but this last scenario tends to be contained to older properties. for example. old red "flock" wall paper contained a deadly chemical as I recall it was Arsenic, but that was a wall paper used centuries ago
As far as spores from one property entering another, very, very limited, OK odors from cooking can permeate, but that is a gaseous transfer
Yes Dry Rot does from time to time produce spores, I have seen it [about] three times in 30 years? the D/Rot forms a so called Fruiting Body, from which millions and millions of rust coloured spores are emitted, in an empty property all surfaces can be covered in this rusty coloured material, not a health hazard either.
Ken.