X2 Visa and transit visa?

As someone from The Netherlands, I'm on an X2 visa in China right now to study here for half a year (feb-jun). In my last week here, I'd like to go to South-Korea (18-25 June), then come back and hand in my keys for my student dorm and stuff, then leaving the 30th of June for Malaysia. Would that be possible? I'd have to fill out my departure card to go to South-Korea I guess, then on my way back I'd have to apply for the 144 visa, and would I be able to spend the days in the meantime in my dorm room instead of a hotel room? Hope you'll be able to answer my question, thanks a lot for taking the time reading this anyway!