It’s the threat of danger that matters.

Correct! It is the threat of danger that matters. Domestic violence as you described is threatening and abusive, and therefore violent.

Is it the same thing when the property is owned by a company, not a person?

Is graffiti terrorism? It’s property damage. It can be ideologically motivated. If someone had spray painted the cars, instead of lit them on fire… would it still be terrorism?

Who was threatened here?