I agree with your assessment, but I think the reason you don't see strong state socialism in a strong democracy is that the state is too corrupted in such a situation. Those with power are seldom (if ever) in the same boat with the people they make the rules for, but with state socialism this disparity is even less tolerable since the the point of the system is to share the means of production much more equitably than ever happens.
I sort of agree. If you look at the Soviet Union for example, it was pretty far from what a socialist society is supposed to be. Workers had no control over means of production, or much of anything else really. It was more of a totalitarian state. But you have to remember there are several ways to achieve socialism, not just through state socialism. Libertarian socialism for example, specifically rejects the idea of using existing state structures to achieve socialism, tries to avoid large concentrations of power, and instead focuses on more direct forms of democracy.
USSR was absolutely a totalitarian state. Socialism can only work when it's voluntary. State socialism is imposed through force, and it can never work because it is stealing by nature of it being non-voluntary. If you had a voluntary society, socialism could work, but I doubt it is ever practical because human beings are hard-wired to be selfish. Voluntary socialism requires unanimity, which seems unlikely except in small groups. I can't see it working voluntarily for a complex society or entire nation. It only takes one person to disagree to make the system not unanimous, and therefore not completely voluntary.