Well, what's your question? Why does it require a blood sacrifice? Or how can the innocent die in place of the wicked?
I'd be careful working on that assumption. It may not be correct. Using her own brain to reason is what got Eve in so much trouble. "Oh, it looks so pleasant. Ummm, it tastes so good. Surely, this serpent is right. I'm not going to die." God's command was that they not eat of the tree. He didn't really seem to leave open for them the choice of reasoning it out among themselves and deciding what 'should' be right about eating the fruit, even though He gave them the same complex thinking system as you have. Be careful.
How can the innocent die for the wicked? Because in this case God says so! It isn't some natural and logical conclusion that we can reason through. It doesn't make any sense to us, just as you have pointed out. But God has established that for all those who would believe in the testimony and sacrifice of His Son, that they might share in the promise of eternal life because the blood of His Son was reasonable atonement 'to Him' for our sin. You don't have to understand it or be able to explain it. You just have to believe it! That's what the Scriptures constantly impress upon us - believe, believe, believe. I don't read much in there about us needing to be able to reason it all out so that we understand all that God knows and understands and establishes as righteous. Sure, there are some things that we can pretty clearly see the reason for, but there are others that we can't.
Why did God part the sea for His people. Why not just raise them up in a cloud and carry them over to the other side? Why not just make them to walk on water like He did His Son? Why not just make them invisible to the Egyptian army so they could have just walked right past them?
Why did God kill every first born in Egypt? Surely they had suffered enough loss in dealing with the boils and the flies. Why not just kill the first born of Pharaoh? After all, he was the one that wouldn't let the people go.
God has said that blood is required for the remission of sin. God said that and so I believe that. Why does it require blood for the remission of sin? I don't know. I could offer up some guesses, but I can't tell you with any real certainty that I know why God requires blood to forgive sin.
How can the innocent die for the wicked. I don't know. I can make an educated guess about it, but I really don't know why God, in His divine wisdom declared that we could be innocent through the shedding of the Son's blood. But I know that God has said that it is the truth ---- for all those who, wait for it....believe.
Even if I were to tell you why God has determined that things are the way they are, what evidence would you have to know that I was right or not? Would you believe me on faith? Well, don't believe me, believe God. That's a part of what faith is. Even though we may not understand the 'why' and 'wherefore' of a thing, we trust by faith that if God says it, then it is a true thing.
God bless,
In Christ, ted