Then shouldn’t we be running openly as communists and not hiding and obscuring our positions?

It’s an interesting question, I see merit on both sides. Especially considering places like the USA where red scare rhetoric is still embedded in the mainstream, making ideas like democratic Cuba sound insane to the average person. Might as well be saying Nazi Germany was democratic.

So, what visibility and radicalization power is achieved if the party is perceived by the vast majority as obscure crazies who get less than a thousand votes?

Obviously you’re correct about association, I wouldn’t say that an openly communist organization should be watering down positions like that. It would alienate any actual communists outside of the org, open up easy targets for sectarian orgs, a whole lot of problems. I’m more talking about how someone like Bernie $anders helped bring a huge number of people towards socialism and even into the communist and anarchist pipelines, despite openly endorsing capitalism, imperialism, Zionist ideas, and preservation of private property. Or how the Nordic Model being mistaken for socialism will make liberals interested while telling them the truth about Cuba will make many of them simply stop listening.