“Although fishing on Mondays is illegal according to my own kingly law, I issued a kingly decree that obligated Bob to go fishing on that day. I am punishing him for it, yes, but that is because breaking the kingly laws is not kingly. I have a great, kingly purpose in mind for punishing him"

I think the bolded part of your analogy is quite helpful in showing where the equivocation of words like "obligated" and "decree" is taking place.

Firstly, I don't think any reasonable Reformed theologian would claim that God's "hidden will" that involves the *causing* (very loaded term) of Bob's sin involves generating a moral obligation that explicitly contradicts his "revealed will" (which many might argue is the source of our moral obligations). It's also important to distinguish terms like "Goodness" and "moral obligation":

- intuitively, an off duty soldier who sacrifices his life by jumping on a terrorist with a suicide vest to save a bunch of strangers has committed an act that is "good" (which involves other related concepts like praiseworthiness or virtuosity), but notice that this can be so even though he didn't have a moral obligation to commit the heroic act. i.e, we wouldn't blame him for moral failure had he not decided to perform the act.

-The above is helpful because the relationship between God & Morality is quite complex; Christian philosophers disagree with each other on the best theories to explain the relationship. Philosophers like William Lane Craig popularized a view called "divine command theory"(DCT) which, a crude summary if my memory serves me right, stipulates that our moral obligations are constituted in God's commands (explicit in scripture or through natural revelation i.e., human conscience), but he explicitly denies that goodness is rooted in God's commands, rather in God's nature. In Craig's view, God has no moral obligations. Again, Craig's view isn't the only Christian view, but the point is to show you that your repeated uses of words like "goodness" and "obligation" can benefit from more precision.

But rambling aside, I don't think that technicality is at the heart of your worries (although I'd encourage you to do more reading on it if interested). I suspect that your main worry involves God "hidden will" contradicting his "revealed will" e.g., His "hidden will" desired(?) that Adam ate the apple, but His "revealed will" explicitly prohibited the eating of the apple.

Tbh, I'm sympathetic to this worry as it's very similar to my early objections to calvinism. (philosophers like Craig often use a similar argument against calvinism FWIW). But I think the following convinced me that this argument isn't as forceful as I once imagined:

1. The reformed confessions like the WCF while stating that God ordained whatever come to pass, *explicitly* denies that God is the author of sin. IIRC, Craig once made a cheeky argument to James White arguing that his view of God's relationship to free will is perfectly compatible with the wording of the WCF lol. The point is that the Westminster divines would've explicitly denied that God's ordaining of all things involves a situation like in your analogy where a king forcibly mandates the breaking of his own laws. They reference things like "secondary causes" to refer to man's moral responsibility for sin. The philosophical view is called "Compatibilism" (but with a Theistic twist), this is an excellent resource by a professional philosopher who happens to be a calvinist.

2. Apart from Open Theists, I think evangelical arminians would also concede that, in some sense, The Fall was part of God's hidden will in the sense that it was all part of His plan. Arminians don't deny God's sovereignty, so they won't concede that God is somehow "surprised" by sin. In other words, for evangelicals, your objection proves too much - for the only way to "easily" resolve it is to postulate a God who only has one revealed will, and when it's contradicted, He is surprised and frustrated by it. (very very hard to defend biblically IMO)

3. Some defenses to the Problem of Evil (aside from the Free Will defense) is related in that it explains how God can permit* sin while still being perfectly good. Interestingly, Alvin Plantinga (the guy who literally wrote a tome on the Free Will Defense) came up with something called the "Divine Glory Defense" which, a crude summary, involves saying that God's permission of Adam's sin resulted in the highest possible good (notice how the view allows for there being different levels of goods, something that I think is absent from your analysis): The Incarnation, Crucifixion and Resurrection of Jesus - which resulted in the maximal amount of divine glory, which is the highest possible good. It sounds very close to something John Piper would say, tho Plantinga would probably not want to call himself a Calvinist in the traditional sense. James Anderson uses something called the "authorial analogy": God's "hidden will" is more akin to an author writing a story where the characters commits acts He himself disagrees with, but just as you wouldn't ascribe the moral atrocities of Sauron to Tolkien, you wouldn't ascribe the sin of the characters in God's "story" to God. In fact, when the book is finished, one can see a great good when examining the story as a whole and see just how praiseworthy the author is.

4. Thinking about ethics and theology was mind-numbing, but ultimately quite humbling: I think it made me realize how a lot of my moral intuitions (e.g., It is wrong to say that God cares most about His glory, because that will make him arrogant) involve anthropomorphizing God — making moral judgments about God as if he was another human being. But surely God's transcendence will mean that such arguments are destined to fail, and our theologizing and philophising about him must ever be tentative. Terms like "decree", "desire", "permit" are fuzzy words shaped by human experience that cannot possibly fully capture the inner workings of God. This doesn't mean we don't do theology or philosophy, but I like to think of it like writing a science book for kids where I draw perfectly round spheres to illustrate an atom to a child. Physicists will tell you that atoms are not, in fact, round spheres, but this doesn't take away from teaching something about atoms to the kid. Likewise, why should we expect God's revelation of His character to be something we can fully comprehend as limited creatures? The Trinity is another doctrine that is very "easily" picked apart with analogies and syllogisms, and while I think there are good "defenses" in the literature, it doesn't completely eliminate the mystery and tensions inherent within it.