Personally, I don't believe Adam and Eve were literal, historical figures.
If we do that where do we start believing the Bible narrative, at what point do we say now I believe this story.
I believe the story is real but it’s placed in the context of an allegory type setting.
Jesus “…was foreordained before the foundation of the world,” 1Peter 1
So the fall was preplanned, he didn’t set the fall in motion without having a plan to save us first. Adam did represent us, he and Eve made the decision to partake of to fruit for us. How much they understood of what they were doing we’ll never know.
God said let us make man in our image and after our likeness, once Adam partook of the fruit the Lord says man has become like one of us to know good from evil. Must have been part of the plan. Or do you think it was an accident?
I think of the command not to eat of the fruit more like me warning my granddaughter, ‘don’t touch hot!’ I know full well she must someday touch the hot oven for her to understand and appreciate what hot is.
You have asked a lot of good questions and brought up some interesting alternatives.
When talking with nonbelievers about the Garden scenario: I do not press the concept of taking it literally, but go over the message.
The New Testament writers speak of Adam and Eve as being real people and not allegorically, so should we trust their insight?
Who parented (or programmed) Adam and Eve to adult maturity (knowing the meaning of words, knowing how to name the animals, knowing how to treat each other, knowing how to tend the garden)?
Was God a really good parent to Adam and Eve?
How could it be fair for Adam and Eve to negatively impact the rest of us, if they were not the very best representatives we could possibly have?
If I felt I could have done better than Adam and Eve, than has God treated me unfairly, by not putting me a Garden type scenario?
You make a big deal of the fact we have after they leave the Garden: “Gen 4: 1 And Adam knew Eve his wife; and she conceived, and bare Cain…”, but we do know it was not a virgin birth, so does the fact we do not have it expressly said earlier “they had sex”, mean they did not have sex earlier?
Christ’s crucifixion was foreordained, so does that mean everything was foreordained or could somethings just be foreknown by God but not made to happen that way by God (some limited free will acts by man)?
I with my limited knowledge of man could tell God before placing man in the Garden situation: “Man will eventually sin under his own power.” So does that mean God made Adam and Eve to sin?
Sin was inevitable, but was sin also necessary?
Is sin man’s big number one problem or is the problem; getting mature adults to humbly accept God’s charity (Love/mercy/grace/help) in the simple act of humbly accepting God’s forgiveness as pure charity?
Since Adam and Eve sinned with the “nature” they had would our nature have to change in order for us to sin?
Adam and Eve’s sin brought about some curses and hardships, but being disciplined hurts while going through it, but if done with Love and correctly accepted should it not benefit the child?
Is death in and of itself “bad”?
If we understand the objective, was the garden scenario a lousy (impossible) place for mature adults to fulfill their earthly objective?
Would you prefer to be in a place where your eternal close relationship with God was dependent on your personal ability to obey (the Garden) or be in a place where your eternal close relationship with God was dependent on your humbly accepting His charity (where you are now)?