Knowing how the wheel of history spins now has given us the ability to predict it and therefore the power to take our destiny into our own hands and shape history after our desire.

I'm not an expert and still in the process of learning about this, but I would say your understanding of it here more or less lines up with my understanding from what I have read so far.

As I understand, Juche dismisses the idealist world outlook as groundless and also rejects mechanical materialism, and holds that the dialectical materialist view is the scientific view of the world. However, it is considered that merely holding a dialectical materialist view does not automatically cause people to start using it as a tool to change the world to humanity's benefit, which is the question that the Juche idea is mainly concerned with: defining and promoting humanity's role in changing the world, and increasing peoples' consciousness of this role. As I understand it, Juche promotes the concept that humans (as a collective whole) not only can but should center themselves in changing the world to benefit them, within the real scientific limits of the world, i.e. with the knowledge of the laws of nature and society which operate independent of human's will. This is seen as a necessary attitude in humanity's emancipation from oppression, as simply having a dialectical materialist view does not necessarily cause people to start acting on humanity's behalf even if it does give them an accurate scientific view of reality's motion.

Texts about Juche seem to primarily focus on asserting that it is correct for humans to center their own needs in how they shape the world, and also focus on discussing humanity's historical pursuit for independence and methods of preserving that independence when it is achieved through progressive revolutions, with the primary focus now being the struggle to end imperialism and capitalism and to defend and evolve socialism, in order to remove exploitation from society and continue on humanity's path to pursuing independence from all restrictions, both natural and social, overcoming them with a methodical and scientific understanding combined with an attitude of intentionally centering human needs and desires in the way humanity consciously shapes the world.

If someone sees something wrong with my understanding, please let me know. I am still in the process of learning about this.