aChristian:
You forgot to mention the most important detail of the story of Adam & Eve.
It's Lucifer.
The simple "test" for perfect men was actually easy to fufill. God was sure that this test would not fail. (Note: He didn't "chose" to look into the future, since pre-knowledge is just the same as pre-determination..)
No. The complexity of the situation has been evoked by Lucifer's appearance as great seducer. Sure, God even would have had calculated with that betrayal, and he knew, that the things in such a case would become very complicated; but he is a God who nevertheless keeps his word consistently.
Certainly, Lucifer (Satan) had calculated that the price for God in such case maybe would be too high (he knew that God had to offer his son for reimbursement). But this calculation had failed. God YHVH (JHWH) had proven himself as absolutely consistent.