Thanks for the translation!
Imagine having a brat of a big sister, and a father that doesn't listen to and do the shit, sorry but I think Jake being salty like this can't warrant me that much complaints as of now.
He has to be the one to nag at them from a very young age, I imagine, from his father's stubborn and awkward, dense butt, and his sister's frequent tantrums and tendencies. Even so, he's advising his father about what his (original) big sister would like. For me, that just shows he still pays close attention to them even though he wants to complete his "the way to being a ghost" online course.
Other than the fact he isn't stopping the crown prince's bullshit towards his own sister (I bet he has the same belief as those around him and it's natural to be those who are around you), I don't think he's all that bad? He has flaws that needs changing, that's it. A human hasn't live if they don't have a few loose screws that needs fixing. And he isn't a human that needs his jail locks fixing like the prince. (Unless you don't count his murdering but that's his job as well.... That's a whole another level of topic.)
Though I do think that's not how you should talk to people older than you, even if you hate them. Just curse inside your head, and curse back if they cross the line, dude, like damn. "What is the purpose of your life?" To not be the crown prince's wife, obviously. You kiddos always read in the dark, go and get some glasses. Do something about that beloved jerkward prince of yours while you're at it. Go to a date, have him propose, etc.