It surprised me that False just casually gave that Latin analogy, it demonstrates a deep understanding of Earth’s culture for someone who have never been to it and had to learn everything second-hand.

I think your reading of the language is correct. At the very least, the two versions of Japanese have diverged enough over time that they aren’t super comparable anymore, beyond things like individual kanji meanings.

I think that the Hopleys are falling prey to an aristocratic form of natural selection. In this episode, not only do we see Laurel decide to back off Makoto, but also Princess Lily after she is warned by False. They are both smart enough to realize that if they push too hard on this person, it could easily be the end of them. However, the current Hopleys heir seems to lack the tact or intuition to back off a self-destructive path for the sake of revenge for some perceived slight.