Tonus, oooofff...these are tough questions. I'm already feeling like I'm sinking in quicksand just thinking about answering them 😅. I'll share what I believe.
Tonus -I think it's a question of whether god was satisfied with this, and why he would introduce a factor which unraveled his utopia.
Genesis states God was satisfied with his creation, he saw it as 'good'. Genesis doesn't imply anywhere that God introduced a factor to purposely unravel what he saw as good.
But where does the serpent come from? God must have created it.
Indeed, God created the angels, including the one now known as the snake. And based on the actions of many angels (materializing into men for ex), they too were created with the capacity to subject to God or not. The snake clearly didn't accept the rules and limitations imposed on him by God.
Did he do so with the understanding that it would work to undermine paradise and trap humanity in centuries of suffering? Were the humans ready for this kind of test? If not, was it fair.
Again, this was clearly not God's intention (considering the entire Bible). God did not set up his creation just to simply fail.
The point was for humanity to be given the chance to express humility towards the Creator. To recognize him as God. God expressed his superiority from the very beginning. He never hid this from his creation. He never called his creation equal to him.
Now, to a person of faith, God loved man first. It wasn't about subjecting man to a terrible existence. He gave Adam everything he needed, first. This is what Genesis states. After God gives man everything first, he gives man one simple rule. It wasn't vague either. There was no trick to it. No deep comprehension of spirituality and philosophy was required.
Adam knew he was inferior to God. Adam was familiar with the concept of affection and appreciation (for his wife for ex). He knew God had given him everything he had. Finally, God warned him that he would die, in effect lose everything, if he went against the rule.
But none of this compelled him to obey the one ridiculously simple command.