1. The Soviet union did not order China to attack UN troops. The Soviets were never powerful enough to order something like this, right after the conclusion of a civil war and brutal Japanese invasion. If they were, there would not have been a break-up shortly afterward.
2. I don't think the Soviet being a control freak is the reason for Sino-Soviet rupture. Even after public denunciation, the Soviets still delivered prototypes and all the blueprints of Mig-21. Your impression of overbearing Soviets might come from Communist propaganda about "three-year natural disaster." That was purely to cover up Mao's catastrophic "Great leap forward," a complete man-made disaster that the Chinese Communist party refuses to allow a full investigation to this day.
6. The Sino-Vietnam border war was China's admission ticket to Western block. Normalization of relation with US followed immediately and arms sales were permitted again. As for the military winner, Vietnam, I would say. Chinese army suffered heavy causalities with little to show for. Chinese officers were shown to be incompetent, and the Air force, despite deploying hundred of fighters, did not carry out one sortie against enemy forces. Another infamous incident is when China imported two sets of military radar for counter-battery targeting and one set sent to the front (the other was sent to Beijing for cloning), it was effective enough that Vietnamese sent in special forces and destroyed it. Afterward, only a lowly company commander was court marshaled.
I have found that Communist propaganda is most effective in willful neglect and ignorance rather than outright lies. Lies can be pierced more or less readily, but ignorance hardened into opinions are much harder to change.