I wouldn't worry too much about sounding rude. I have been travelling back and forth every 3 months between Norway and America for 2 years now. My fiancè is Norwegian. The first trip here I thought nearly everyone was "rude". Turns out, they just have a no frills way of asking for/answering/demanding .... talking!!! Lol .
I said, "The boy will not come home," and it was marked incorrect. I'm assuming this is because "come" isn't quite close enough (e.g. drar ≠ kommer), but colloquially I think this would be right. And I think I've seen instances of "drar hjem" used for "come home"? But maybe I'm mistaken. Someone who's better with Norwegian grammar and vocab than me: What am I missing?