you're making an assumption my fine fellow frog; personifying god. that's an incredibly narrow definition of what god is. a bearded man in the sky who grants wishes is a genie, not god. god is the totality of existence. the problem you're facing is at a subjective level, the nature of the universe is arbitrary and obscene, and if god can allow things that seem subjectively evil, then therefore he is either unable or unwilling to intervene. however, since god is the totality of existence, he is the child with lukemia, the cancer that will kill them, the doctor that attempts to treat it, the parents who birthed them, the space in which they occupy, the building that houses them all together, the planet they exist on, and the universe in general; infinite layers of concentric micro and macrocosm. christfags describe this concept obliquely with the holy trinity: the father, the son, and the holy spirit.  the last part of your answer aligns more closely with reality. humans arent the center of god's plan because that's an anthropocentric notion. none the less, you are at the center of god's plan specifically, because in a literal sense he has given you the tools to shape the nature of your own existence, and the ability to have metacognition about the nature you interact with the universe. john milton nailed it in paradise lost when he says "the mind is its own place, and in itself can make a heaven of hell, a hell of heaven." if your kid has lukemia and dies, you can let it consume you; this nihilism seems logical. however if you choose to campaign and raise money for research, you wind up funding hospitals, employing doctors, creating scientific breakthroughs, yadda yadda yadda. i can go on, but small actions have a large impact when you account for the causality associated with them. willfully changing your perception of reality changes the nature of existence based on how you interact with it (cont).
Canada