I fully agree that the purpose of a system is what it does. That's why the purpose of existing socialist states is to uplift the working people, and work towards a fully collectivized society where production and distribution are run according to a collective and scientific plan. The importance of the primacy of class as the basis for our understanding is that class is the basis of the state. There is no such thing as a state that is not a monopoly on violence in the hands of a ruling class, and this extends to states that are under the control of the working class.

Regarding freedom of speech, Marx observed that there is no such thing as freedom of speech in class society. Socialism is necessarily still within class society, and ergo capitalists must be oppressed by the state, lest they overturn it. In communism, there can be actual freedom of speech, because by that point class has been eradicated. Marx fully aligns with my analysis of class society, this is part of the theory of the "dictatorship of the proletariat," of the proletariat as the masters of society.

The same applies to assembly and association. The working classes should be able to do so as a class. Capitalists should not be able to do so, nor should those that work against the interests of the working class.

As for removing ambiguity, I can hardly make an exhaustive list, but in short the same socialist states supported historically by Cuba and the Black Panther Party: the DPRK, Vietnam, Laos, PRC, and former USSR, to name a few. I explicitly mentioned Cuba and the Black Panther Party because both support every one of these states, including the DPRK, but those that oppose "tankies" tend to exclude Cuba and the Black Panther Party as "tankies" despite holding the same political positions and having/supporting similar structures and economies.

I believe all states necessarily are "authoritarian." I think, therefore, the class in charge is the most important factor, meaning I support worker states and the authority they impose on capitalists and reactionaries, as far as is necessary to protect the gains of socialism.