How would this "democractic" system deal with Sybil attacks?
You start off talking about ideas and then jump over into the reward system. Is there any censoring of ideas taking place here via the reward system? I don't think so. Ideas are free to spread according to their subjective content value. It's not like you have to have high SP to resteem something.
I don't believe that there is censoring via the rewards system, but some people do. I agree with what you said about content value.