To start with, I'm a technocrat with leanings towards anarchism and Marxist ideas. Now, what I'm talking about here is a scenario in which a modern socialist revolution happens.
I'm going to simplify things as much as possible for the sake of brevity. Specifically here I'm referring to the early days of the USSR&PRC. As can be seen throughout history, the founding which a country is built upon has profound significance for the rest of its existance. Now, I've noticed that the authoritarian version of socialism practiced by Stalin in the USSR and Mao in the PRC, has a lot of support on communist forums. Imo, it would even be safe to say that the plurality of modern communists favor an authoritarian version of communism (like what I referred to before) to a liberterian/anarchist one. So we're going to leave the anarcho-communists and related schools of thought (which I'm more inclined towards) out of this discussion, and focus on this phenomenon. The pervasive streak of authoritarianism in communism is most likely due to the fact that the two major socialist experiments were, at their founding days, dictatorial and repressive, from which it has been carried over from.
Now, you can argue that the "dictatorial and repressive" element I spoke of is false, or an exaggeration. To argue that it's entirely false is, in my humble opinion, an untenable position. Now, I'm not going to look at every single thing here and analyze how bad it was, that's not the intention. Let's grant, for the sake of argument, that the "official version" is 50% true (it hurts to simplify things so crudely, but bear with me), I mean the oppression was half as deep or something. Even if you grant this generous proposition, you're left with some nonarguable governmental actions, just to name a few: Purges, extrajudicial disappearances of actual and perceived dissidents, etc
Now, my questions are (speaking of the time after the revolution):
1) Should it be possible for people to be punished without a chance to defend themselves in a(n actual) trial?
2) Should dissidents, discontents, be "dealt with"? If yes: If force is necessary, should it be used? Lethal force?
3) If not, what concrete steps are going to be taken to avoid and learn from the mistakes of the past?