I won't answer about Juche since my knowledge about it isn't enough to give a good reply.

There's no such thing as "Dengism", if you're not into philosophy or political theory much, specially Marxism, it's a bit hard to understand because it's related to dialectical materialism and the nodal notion of change proposed by Hegel, but there are no -isms besides Marxism and Marxism Leninism. "Dengism" would be better understood as a further development of the Marxist Leninist theory by Deng Xiaoping, or Deng Xiaoping Thought. The only reason why people see China today, or the policies carried out by Deng as something xeno is because he formulated the importance of the role of a socialist society within the international market in the context of international bourgeois rule. People think "real communism" is when they close borders, produce everything nationally and do not let outside influences, and nothing can be further from the truth, not only it is physically impossible to do so, but also contrary to the international Marxist ideals of internationality.

What Deng did was to allow foreign capital in order for the bourgeoisie of other countries to invest in industrialisation because they could provide cheap labour, therefore accelerating the process of accumulation of national capital and the development of the productive forces. This is something no socialist country would frown on, they just had the chance to fully implement it and they had the history of past socialist experiments to learn from their mistakes.