2. The ideology in USSR was exactly the same - the war against evil west. There were a lot of propaganda about decaying western society and how in 10 years we will build communism and win the Cold War.
3. The economic situation in North Korea is very bad. People would starve there if China would cease it's economic help.
4. Don't think that people there have no understanding of the situation inside their country. In USSR there was an Iron Curtain and totally controlled media but still many people understood the situation and discussed it in their kitchens. People feel the situation very well when they see the dramatic difference between the idealistic picture in government controlled media and in real life.