1) I'd agree that those two things are examples of cults of personality, but the reach is so limited compared to modern-day cults of personality. I don't know how much the average pre-modern Chinese person (i.e., an illiterate peasant) understood about the Mandate of Heaven, or if he even bought into the concept. I sincerely doubt it affected his life in an everyday sense though. Given that the state co-opted the literati even in those earlier times and indoctrinated them, it would be hard to say how much reach the concept had outside of the ruling classes.

2) I would hesitate to call Qin Shi Huang totalitarian in any way that resembles 20th century totalitarianism. I agree that he was on that spectrum but falls short. Unifying weights, writing, burying your opposition alive, etc. is one thing, but intruding on every aspect of society is quite another, and something that was impossible to do, given the technology of the times.