Swordfish Ceviche

Obviously, you'll have made your decision by now, but for posterity:

Swordfish is a deep-sea fish. As such, there are very few parasites that can cross over from its flesh to humans; pretty much the only ones are a few species of roundworm, the worst of which is the Anisakis worm. Swordfish are less prone to roundworm infections than some other fish, but such infections are not unknown. Marinating in acid kills some roundworm larvae, but not 100%.

This means that whether or not you're willing to eat marinated swordfish that has never been frozen is really dependent on your personal risk assessment; we can't give medical advice here. All I can say is that the risk of infection is very small, but not zero.