Well I ask these cause authoritarianism seems counterintuitive to the main philosophy around Marxism. Saying “the proletariat should have greater value and power in a business, since they’re doing the actual labor”, but then rolling over and accepting a dictatorship where the populace has no political say seems nonsensical.
Hence why I suspect the authoritarianism must have come first. So I can’t necessarily agree to “communism predisposing itself to authoritarianism” since it doesn’t make sense for a True-Marxist society to want to accept that sort of government.
As for how to set up the government in a communist-economy state: probably more of a Republic. People elect multiple representatives, and these representatives meet and decide on policies for the country and how to run it