“... you are not ingesting invisible parasites or their eggs with the raw fish?”
Saltwater fish, especially deep-water fish, are quite safe. Avoid estuary, near-shore, or freshwater fish, and don’t eat raw crab or other shellfish unless you know where they’re from. Lung flukes from Chinese raw crab are still a problem (as are tapeworms and other worms from beef, pork and water buffalo in much of Asia). I will eat most oysters raw, but I don’t eat Chesapeake oysters unless they’re cooked. Same goes for imported shrimp, especially ones from SE Asian shrimp farms.
You seem to have a good handle on where the parasites can lurk in uncooked sea food.