Nah, she's not a useless recluse. She's just highly specialised.
Considering that the flower pot could've been thrown, you can't count the trajectory that accurately. You can't account for the initial force and direction of the throw.
Most likely, if a student saw a cat, they wouldn't react too much about it.
"Expelled due to sudden illness," just sounds so wrong it can't be anything other than a curtain over the truth.
Well, she knows how to insult in a posh language.
Very ladylike to hit someone.
Translation's great. While I can't speak for the exact translation, it fits the situations from what I remember from a year or so ago when I read the novel. Glad you're having fun with it, as it'd be a pain otherwise.