Yea I am also getting the feeling that daddy dearest didn't order the hit. She mentioned that they needed this marriage to avoid some conflict so it was probably a 3rd party who wanted it to happen and hired some thugs. The "message from the Duke" could have been a plant if they left a guard alive or it could have just been the dude being a dick. Her family is cold and dismissive, but they haven't been shown to be abusive. Also she wasn't talked to or disciplined for what she did to the maid , so it seems like her parents were fine with that. It could very well be that there was always this awkward gap due to the "taking over the role of Katarina", or whatever the name is, that neither side tried to bridge. The father might just be super strict because she has a lot to learn as a noble lady, in the "this is shameful" scene we don't see what she did. Maybe she only got the equivalent to a 35/100 on a test. He is a dick for going as far as he did with the scolding, but it doesn't make him evil, or even a bad person.