just because you choose to defy God doesn't in any way shape or form undermine his Godliness or ultimate authority. it doesn't change the nature of who or what He is. to use your example with kids, my son has the FREE WILL to defy me if he wants, but because i currently define the parameters of his immediate reality (lol), if he CHOOSES not to obey my rules, those actions come with specific consequences (being grounded, no tv, etc).
the universal law of cause and effect still works, even in his 6 yr old context. whether he wants to listen to me or not, it still doesn't change the situation (i'm his dad and I make the d@mn rules). my authority isn't remotely in question or even debatable

. either he can listen to me and live pretty comfortably, or defy me and have a pretty miserable young life. it's his call. LOL.
it works the same for God. it's not a matter of whether God is "okay" with us defying Him. The parameters for how the universe operate have already been set. There's NOTHING we can do to undermine what God has established. It already IS what it IS. We've been left with the ability to choose. You can either work in harmony with it, or fight against it and make things harder on yourself. It's our choice.
yeah, we do disagree here, but just a bit. maybe a better word for "free will" as i see it is self-determination. i agree with you, we don't have ultimate freedom because we have to work within the context of the reality we were created in. our universe operates by rules that we have no control over.
but within that context, we have the freedom to make whatever choices we want. however, the choices that we make are subject to the rules of cause and effect, so these choices come with consequences that are destined to happen as a result. free will and destiny to me are 2 sides to the same coin - they are intertwined. here's an example - everyone born is destined to die at some point, but how long you live and what you do with your life is subject to your free will.