Stalin and mao had a great relationship - both personally and diplomatically, but I think the fundamental reason in the split was kruschovs pacification policy. He intended to approach SU to the west and demobilize the soviet proletariat, something that is counter revolutionary at heart and could not be tolerated.
Had sino soviet relations not been destroyed, most of asia (and consequently, of the world) would be socialist.
It would be a matter of time before a world revolution, the defeat in germany would be a black dot in history...
Mao was in a great deal responsible for distancing PRC from SU, with good reason, and he also left deng xiaoping alive, also with good reason.
Nika brought a end to the Sino-Soviet Relations. Nika brought a end to the Anti-Revisonism in the CCCP, a sad day, and Deng brought a end to Maoism in China after Mao's death. they basicly copied the Russian Revisionist way of taking a Socialist leader and denouncing him and making them in control.