Then Stalin shouldn’t have insisted on the independence of outer Mongolia, the use of Port Arthur (Lushunkou) as joint Sino-Soviet naval base as pretense to station Soviet troops in Chinese province, refused to return the Chinese Eastern Railway (Changchun Railway) rights to China, and keeping Vladivostok (Haishenwei) that the Russian Empire annexed as part of the Soviet territory

So, were the actions of the PRC guided by realpolitik (which requires abandoning grudges), or by grudges like these ones?
Also, not sure why you want to claim military cooperation between the USSR and the PRC being a bad thing.

All these infringed on the Chinese national sovereignty

Notably, they all happened a long while prior to the split, meaning that they couldn't have influenced the supposedly-realpolitikal reasoning for the relevant actions of the PRC.

It got even worse after he died, as the USSR turned revisionist and started to expand on its “imperialist ambitions”

You mean when the USSR was helping multiple national liberation movements in Africa, Asia, and the Americas against NATO colonialism? Those 'imperial ambitions'?

EDIT: Also, I find it rather ironic that I hold a much more realpolitikal position regarding the PRC than you do regarding the USSR and other Russian polities.