“You can’t justify killing people with trends, man.” -- Yes, you can. Life has value just as everything else. To look at it from an economic standpoint, a human life has been priced at 5 to 10 million dollars (US), based on what a person spends on their safety (source: More Sex is Safer Sex, Steven E. Landsburg). Therefore, if we estimate the loss of life in a revolution, and compare it to the profit gained by that revolution, and if the profit is greater, our cost-benefit measurement tips in favor of revolution. This principle can easily been adjusted for a political, religious, or social standpoint, with either generic or dollar values assigned to the benefits and detriments. In theory, one should total all of these different standpoints, and determine if the revolution is benefical before deciding to go to war.
"If we clearly have a better system planned out, then people should want to be a part of it."-- However, it is unlikely that those in power would want to, as they've got the power (and thus perks) now, but probably won't post-revolution. A better system will give you more troops for your revolution, but probably won't persuade a corrupt leadership.
"But the censorship is to cut out all the bad stuff that society produces.”-- The question is, who gets to dictate what the 'bad stuff' is.
"Say we have a shortage of a particular skill, we just open the valves for those kinds of people to come in. And they balance us out again. In that case we even choose who comes into our country, and new stock does nothing but improve our society.”-- Once again, how can this be enforced? While may of Plato's ideas work well in theory, they fail at the first scent of practice.