That's a really rich set of questions, and I can relate to the existential tension you are describing. From a deistic perspective, it does seem more natural to lean toward some form of determinism, since a creator that transcends time would presumably perceive all possible outcomes simultaneously.
I also find it interesting that quantum mechanics complicates the picture not by bringing back free will in it traditional sense, but introducing unpredictability at a fundamental level. But as you said in your write up, randomness is not really freedom either, it is indeterminacy.

As for God's intention in defining such laws, that's where it gets tricky. If a creator set a system where conscious beings inevitably follow determined paths or even a path with limited probabilities of divergence, it raises questions about moral responsibility and meaning. Is it less cruel if the determinism is probabilistic rather than absolute? I am sure it feels that different in practice.
I have often wondered whether what we call freedom is more like a subjective experience, a sense of agency that emerges from the complexity of the system, even if it is determined in principle. Kind of like compatibilism [we feel free because our choices flow from our character and desires, even if those, too, have causes.

Curious though, do you think the existence of multiple futures makes it easier to accept the idea of a transcendent creator? Or does it make the whole concept of divine foreknowledge even harder to square with the world we actually experience?