She probably know heās stuck in a loveless arranged marriage. But that doesnāt mean her actions are justified.
I think he is the reason for the ripped shirt/blazer slipped from her shoulder. She made him stop by crushing the glass because she didn't want to fight back using her voice (so others stepping in could interpret it as him blowing up at her/them fighting) She does not want to reveal their relationship (yet) because it would destroy her professional image/armor she built.
oh barely! I took a beginner's course. But I watched dramas for years and can see inaccuracies in the subtitles (In my head I translate more word-for-word, using the subs to "fill in the blank") and differentiate the level of politeness in speech, the way of address etc. Nobility has also been a special interest of mine. I research many (k/j/c) historical dramas I have watched. In Japan, for example, the royal family is that special, you cannot even air a scene where an actor is portraying the emperor. The princesses are never adressed/interacted with normally. This drama, for me, is an interesting look into what Korea has been grieving, yearning for, an alternate reality, artistic mixing of nostalgia and satire.