The iNat Help on geoprivacy answers some of your questions:
https://help.inaturalist.org/en/support/solutions/articles/151000169938-what-is-geoprivacy-what-does-it-mean-for-an-observation-to-be-obscured-
including about taxon geoprivacy which is obscuring that happens automatically based on an observations ID and location.
But otherwise, basically just use your best judgment. You can also delay posting your observations or not post at all if something is very sensitive. There are a lot of other threads on obscuration and how to make decisions about it, so you could look through previous forum threads too.