The beauty of the lesson you COULD have taught him is just what I posted, Genesis 3:22-24.
God had already given them the immediate punishment of the childbirth pain and the sweat-of-the-brow, working the soil. The true love came when He blocked their continued access to the Tree of Life. By doing what appeared (to them... and I guess, you, too) to be even more punishing, He was actually putting them in line to one day be able to receive even more gloriously ETERNAL life than that which they enjoyed in the garden when Jesus finally came and took care of the punishing law they were now going to have to live under.
My only question was that you would withhold the most wondrous part of the Garden Story by saying God kicked them out of the home he provided for them because they disobeyed. No, they got their "spanking", as it were, in the curses pronounced on them. The expulsion was, though they didn't recognize it, the "leading" of God into the plan of redemption.
And the "separating Himself" from them was totally contrary to what is shown in the story, in which He remained right there with them, first, searching them out when THEY were separating themselves from Him by hiding, then talking with them, then clothing them, etc. And Eve even said, later when her child was born, that this "was the child God had given her."
This is the kind of love I think a child needs to understand.... not a Father-figure who runs His kids off in anger, barring the way for them to return home with a flaming sword. I think a child needs to see, that right from the very first sin, that God set up a plan to bring them home to Him.