So, first off, the usual disclaimer. I'm a Christian but not a fundamentalist. I don't take the creation account or that of the fall literally.
I do believe the myth speaks to us on various levels. It is the foundation of our faith, warts and all, so to speak.
At the first level, I think it's about personal ego, the moment when you realize that you're, well, you. And this is followed shortly by the realization that you can and will die one day. The thing I call "I" will cease to be, at least in the sense that I currently understand myself.
As far as the fall goes, I think it goes without saying that you can't break a commandment you can't comprehend. So it's a potentially dangerous line of thought to take the account literally. What I think the story does, though, is retroactively apply a more mature understanding of 'love your neighbor' to the beginning of personal ego. Understanding myself as 'a' self opens me up to the possibility of understanding others and working for their good as well as mine. But the author frames this revelation as a tragedy, because it also means understanding that we are incapable of doing everything we can and should for our fellow human being. From the moment we understand 'self,' we will always feel trapped by it. Torn between what we want and what we ought. As Paul says, "Although I want to do good, evil is right there with me."
At any rate, I think you're right about why immortality can never be seen as a gift until we are transformed inside as well as out.
"Immortally mundane beings"--I love how you've phrased that!
That is a great C.S. Lewis quote that puts our relationships in perspective.The Tree of Life was not forbidden before the fall, right? Not expressly. It was the eating of the Tree of Knowledge that linked Adam and Eve to death (Genesis 2:16-17) - "when you eat from it, you shall die." This tells me that Adam and Eve could have been eating from the Tree of Life in the Eden days. They no longer had access to the Tree of Life, though, after getting exiled from Eden. But they were still immortal beings, just not physically:
"There are no ordinary people. You have never talked to a mere mortal. Nations, cultures, arts, civilizations - these are mortal, and their life is to ours as the life of a gnat. But it is immortals whom we joke with, work with, marry, snub and exploit - immortal horrors or everlasting splendors. This does not mean that we are to be perpetually solemn. We must play. But our merriment must be of that kind (and it is, in fact, the merriest kind) which exists between people who have, from the outset, taken each other seriously - no flippancy, no superiority, no presumption.” -CS Lewis, The Weight of Glory
God could have made them immortal in the first place, too. I wonder if that, in part, is what is meant by "image of God."
I'm agreed that can be problematic. On the flip side, not being a literalist, I believe even flawed texts can be used by God to speak truth, sometimes more personal than universal.
A corrupted Shakespeare folio still tells us more about his work than nothing--though it would be dangerous to pin our entire understanding of him on a single passage!