That is absolutely true which is why there has never, and will never be a communist government. You cannot have communal ownership when somebody is in charge. And in a nation, someone has to be in charge. That aside when was there ever a self-professed 'communist' government that wasn't despotic?

Wouldn't a truly communistic nation have to be a truly democratic one too? Where each person has an equal say in matters, ie one giant committee with no representatives?

Communism is more of an economic system than a political one. The basis of Communism is no personal property, and thus no individual rights; the state owns everything and you own nothing. It hypes the community over the individual. Theoretically you could have a democratic communism, but it likely wouldn't last long as people would vote for more individual rights and freedoms.

State ownership is socialism, not communism. Communism holds that all things are shared as group ownership, not given to a third party, which the government would be. It is a fine distinction between them, but an important one. Governments claiming to be communist are almost universally socialist. The term is frequently misused.

I always had this feeling, that the Federation of Star Trek was communist

No. The Federation has gone beyond titles and names. Everything is light and wonderful. All elections are fair. If you don't believe me, just watch the last episode of season 1. :sunny: