“Knowing that something will happen is never the cause of it happening.”
It doesn’t matter what the cause is - you will do what’s preordained.
The ties between cause and effect become irrelevant in a world with an omniscient God. They are simply a string of events that he causes to happen at his whim and they may or may not be related.
To the extend that God imposes some fairly constant relationship between certain events, that helps us - non-omniscent humans - to approximately predicting what’s likely to happen. (eg, you jump off a cliff you most likely die)
Every so often humans discern some of these relationships. It’s what we call, the “laws of nature”.
Your problem here is that once again, you are attempting to argue against the character of the God of the Bible while selectively ignoring key relevant aspects and blithely imposing your own unwarranted ideas, necessitated to justify your rant against the same. Rather than the omniscient God causing events to happen "at his whim,"as having no plan or purpose, what Scripture teaches is that God both allows and sometimes proactively causes events as having a definite purpose, whose "understanding is infinite." (Psalms 147:5) I can argue against the God of Mormonism, but I must be consistent with its description in so doing.
Declaring the end from the beginning, and from ancient times the things that are not yet done, saying, My counsel shall stand, and I will do all my pleasure [will]: (Isaiah 46:10)
He hath made every thing beautiful in his time: also he hath set the world in their heart, so that no man can find out the work that God maketh from the beginning to the end. (Ecclesiastes 3:11)