[NB I'm not trying to defend the Soviets, who were a thoroughly unpleasant bunch, but the colossal failure to understand their motivations and just how one side the Cold War was for most of the time almost ended things.]
The West had many reasons to believe the USSR was stronger than it was, hawks on the right wanted to believe it, fellow travellers on the left wanted to believe it, the Russian political system wanted to believe it (and lied to itself repeatedly).
I wouldn't agree with that - I think the Civil war, and the subsequent domestic uprisings were that impetus. Outside of the Second World War, most of the fighting the Red Army did was against its own people.
That is a whole lot of fighting to leave out.
In any case, these things compound. Immediately after WW2, the USSR still felt threatened by the West, which was not an unfounded fear. Multigenerational paranoia about being invaded by more powerful nations is precisely the kind of thing that damages institutions to the point where they no longer serve any purpose but preserving themselves.
If your ideas require you to impose a dictatorship to implement them, then maybe they're not such good ideas.
Under the accounting methods used, capitalist systems of government would dwarf that number. Of course, uneven standards are par for the course.
> It was always the plan of the Marxists to grab all the power and run a dictatorship.
"The Marxists". Do you know how many groups participated in the Russian civil war, how many of them considered themselves Marxists, and how many of them were purged by the sole political entity that seized power? Since you uncritically cited that 100 million figure, I'm going to guess no.
Have you ever tried yourself? It's not a very hard thing to start to compile. The problem here is ideological though. Everything that would be added to the capitalism list would be rationalized away even if it uses the same measurement stick.