You said (in part): (on any rational scale I'm capable of grasping, the 'crime' of learning the difference between good and evil doesn't merit the punishment of horrible death).
I am prepared to admit I don't know all that God knows, or even all about God. You and I may not be capable of grasping the "rational scale" that God employs.
As I read Genesis, God did not say that anyone would die a "horrible" death, but certainly people do die such deaths. Do we blame God for these deaths? If I am advised not to judge other humans (and I try not to do so), I will certainly avoid judging God. I have said on other posts that there is little or no good in this world that occurs without evil, bad, discomfort or pain. Generosity, cures for illness, courage, comfort, sacrifice, and all other good that I can think of exist only in the face of evil or less than ideal circumstances.
I believe we usually look at God from our human perspective, and that is natural--but it may not give us the true perspective. God, I suppose, could have pre-programmed us for obedience, much as He did the animals, but I believe God wanted more from us. He gave us the freedom to obey Him or not, so that when we DID obey and honor Him, that obedience and honor had value. When I make my children clean their rooms, they do it... because I said so. Occasionally, though, they clean the room on their own, just to please me. On these occasions I feel pride in them. The same task is more rewarding to me, and to them.
Sorry for the extended response, but there you go, for what it is worth.
Best regards...