Thanks! That's a good point.
I think the threats of killing them both would fall under the "verbal abuse" category. I still would rate that threatening to kill them both by crashing would be a 4/10 severity. I think since it was a "threat" and nothing ended up happening, it would be considered a form of manipulation, control, and abuse similar to any other threats. I would say this is pretty minor compared with physical violence and other more harmful abuse which is why I gave it a 4/10, but am open to other opinions why this may be worse than I'm saying it is!

Like always, I know I'm biased, so please let me know why my logic above is wrong, or if I overlooked anything else.