They're not bombing them, it's 'just' gulags and death penalties.

Question: Have North Korea ever shoot a Chinese military ship, killing 34 crew members and wounding 171 more?

Yes.

Whether or not this is true, which I'm not going to address, DPRK is 1) not a settler colonial state, 2) not doing apartheid, and 3) not in the process of growing their own borders into neighboring territory, which are three very large and important differences to consider no matter how you feel about DPRK