God did not Punish and Kill them for their Innocence, but rather for their Disobedience.
Naive or not, knowing the difference between Good and Evil or not, they did know this: "Thou shalt not eat of it". Thus said the Lord, their Creator and giver of all they enjoyed.
They Disobeyed. Fot that, they were Punished and suffered Spiritual Death.
It was, as you say, God's will that they should Disobey, and thenceafter be Redeemed. But I think you may err when you presume that it was because this was "necessary" in order that they should "spiritually grow up". I propose to you an alternate view -- what if it's not "all about" Man, at all? What if, in fact, it's "all about" the Glorification of the Son by the Father -- that the Father ordained that the Son would be Glorified as both Redemmer and Judge; and that the entire Race of Man, his Fall, and the redemption of the Elect Church (I'll avoid discussing the mechanics of that election) are simply the objects of that transaction? An End to a Means? In other words, simply the Clay?
I appreciate your thoughts, but I'd urge you to consider my counter-suggestion.
As to your suggestion, let me address it below:
Let me propose to you a different view and then you be the judge.... Salvation makes sense only if we understand that God had to let us fall and die in order that we can spiritually grow up.
Let's consider your theory, and let me ask you this:
The Elect Angels never Fell at all. Nor were the Reprobate Angels offered any possibility of Redemption.
Is it, then, your contention that the Archangels Saint Michael and Saint Gabriel are, well -- "not Spiritual Grown-Ups"?
Is that what John means when he says God is Love? Is it self-love? Self-mutilation for self glorification? Maybe I am missing something OP. Maybe it's just how we express ourselves.
Naive or not, knowing the difference between Good and Evil or not, they did know this: "Thou shalt not eat of it"
If they were perfect they would not have disobeyed. They were therefore not perfect. They were mentally children, provided for, with no needs and no shortages. And children must come of age by leaving their childhood home.
They simply did what they were predestined by God to do to fall from Grace. Why punish them if theirs was not to decide? Where is the sin in that?
The Elect Angels never Fell at all. Nor were the Reprobate Angels offered any possibility of Redemption
Angels are rational beings but since they lack body they also lack bodily passions. Those who were elect (called upon by God) and who turned to God on thier own afterwards remained (naturally they were all elect). Those who fell from God fell on their own -- and for the same reason -- to be "like God."
It's late. Thank you for interesting and challenging viewpoints.