I think generally "socialism" or "communism" can both refer to the mode of production, and the movement towards it (the establishment of the material human community) is called communism. "Socialism" and "communism" are pretty much interchangeable. That's the way Marx and Engels used them.
I never claimed there won't be a transition period, you're the anarchist.
No, "the transition period" is the name for the period for the transition to communism. Using "socialism" to mean "the transition period" is conducive to defining it as its own mode of production, a mistake the Bolsheviks made, which later allowed them to play more and more loosely with the word and use it to mean whatever was convenient. This is precisely why "communism" and "socialism" are today looked at as separate things. But they aren't. There is no stable system of social reproduction between capitalism and communism. That's what a revolution, a transition, is.
Not necessarily
Capitalism doesn't mean "free markets" (what are you, a fucking ancap?). Capitalism means "a mode of production where the ruling force is that of capital". Democratic self-management is entirely compatible with this. They will continually decide to exploit themselves. The poles "proletariat" - "capital" remain completely intact.
Capitalism is fine with a certain extent of the planning of people via things. What the fuck do you think a firm/company/business is? Put on a national level does not break capitalist social relations, capitalist logic will assert itself (black markets, trading between industries, etc.), and the supposed "planning" will reveal itself to all along have been the organization of people by things (the russians were always trying to come up with some mathematical formula that would organize the economy for them, in the 60's it became law for firms to ignore the "plan" if it would be profitable, which shows that capitalist categories never disappeared)
Real soviet democracy would not have made the USSR socialist.
I think all this confusion can be laid to rest by simply asking yourself, "what is capital?".
It doesn't cease being the self-expansion of value just because you cast a vote for it to happen.
No, I'm implying "markets" are in the category "economy".
No it isn't. Primitive communism isn't "an economy". That is projection of current categories into societies where it didn't and won't exist. "Economy" was not separate from the rest of life, There was nothing to differentiate production from anything else. This how it will be in communism, self-development becomes production.
The "base-superstructure" model is part of the critique of capitalism. It does not fit other modes of production. Try explaining to a serf, a lord, a king, a slave, a master, or a hunter-gatherer, the difference between economy and politics, let alone the latter the difference between production and the rest of life.
You're missing the entire point. What is the break, it is one from ideology, not gradual changes towards a break into another ideology.
1. Marx wasn't a Leftist.
"Marx and [I have] fought harder all our lives against the alleged Socialists than against anyone else."
- Engels
2. No it can't. There isn't a "Marxist economics" or a Marxist "politics", there is a Marxist critique of political economy. Marxism is an (open, expanding) whole doctrine of relentless critique. Ruthless criticism can't be broken into pieces.
That's not what I mean, I think we may be talking about two different things.
Marxist doctrine is not a thing in one's head, it is a system of critique.