Hence, the simplicity of the command.
So? The ability to understand the words, and the meaning of the words, is different than understanding the moral implications of the command. Without the knowledge of "good" and "evil", there is NO concept of "should" and "should not".
It wasn't even about a single, isolated tree beckoning them. It was a garden. There were trees everywhere. All blending in and looking the same or similar perhaps.
I'm not sure why that matters.
If I'm understanding your question correctly, that mechanism was trust. Assuming that Adam and Eve were as ignorant as you propose, it would be trust.
If someone doesn't know good from evil, does that person even know the difference between "truth" and "lie"? A lie a false statement made with an intent to deceive. Adam may know the difference between "correct" and "incorrect". But to Adam or Eve, a statement that contradicts God's statement had no malice in it. To them, they have no way to treat it other than new, updated info... new light, if you will. "Oh, you mean God was mistaken?"
You might counter that they shouldn't have believed or trusted anything anyone else said. But upon what basis do they have the ability to make that judgement? The idea that they are being deceived is derived from the knowledge of good and evil. If they are to "trust" God, then they would "distrust" others. What reason would they have to "distrust" others, except for the possibility they may be deceived, and that's beyond their ability to discern of even "know" at that moment.
The scriptures tell us Adam deferred to God, knowing he was inferior to God, not equals. He knew that much...that God, by virtue of being 'superior' would know better.
Ok. What do you mean by "better"?
The scripture also reveals that they understood that death, whatever that was, was not a desired thing. They had enough capacity to put not following God's command as equaling death, as equaling not a desired thing.
I don't think you understand how disabled they were, if they didn't know right from wrong. I refer to my paragraphs above.
As for the ultimate price being justified. People of faith will always defer to God, always. People without faith, obviously never will.
I don't think so. If a mentally retarded child takes a candy bar from a store, do we dole out the death penalty?