So, you do accept the premise that the human sacrifice was required before God was willing/able to render the "outpouring of grace necessary for salvation." This was the premise of the OP. But it seems clear to me that in order to believe this one has to assume that God is sub-human simply because every human is capable of forgiving/outpouring grace on someone who has offended or sinned against them and it is precisely this ability to show grace without prerequisites that makes forgiveness/grace such a powerful force. It is also the central theme to the life of Christ, a life that did not demonstrate the need for sacrifice in order to affect reconciliation but rather that simply poured out forgiveness and instructed his followers to do the same. This is in stark contrast to the death of Christ and the purpose that you describe above.
I do not believe that the Cross was an event which occurred in order to satisfy the “blood lust” of God. As I said, the Cross is part of God’s wrath upon the old and broken human nature- that is to say,he undoes in Christ what Adam has wrought for all humankind. He puts to death the sinful nature- this is in itself an act of grace because it accomplishes what human beings can not do themselves. Perhaps it can be said that, were God to destroy the sinful nature without Christ, that is, impart the grace upon us which restores us to Him, we ourselves- in our darkness- would be destroyed by the brilliance of His light.
Christ descends, Christ incarnates as one of us, Christ becomes the body of sin and presents the sinful nature to God because he alone, in His divinity,
can endure the great purging of human nature that is the Cross and the violent birth pangs of the new creation - and therefore he alone can carry it in its restoration and elevation in the Resurrection.
Could God have saved us in another manner? I’m not sure, and I tend not to consider it. I deal with God as he has been revealed, and the Cross is to me one of the most astonishing moments of God’s self revelation. In a way, totally unexpected,
here in the thorns and the nails the fullness of God, as Son, stands as our brother in the same movement which illustrates to us, and brings to shame, the disorder of human life.
The Cross is foremost a mystery, which will always surpass thought, and it sounds to me like you are caught up in its scandal, as St. Paul himself always said:
The cross is a stumbling block to the Jews and foolishness to the Gentiles.
I am also inclined to believe that “
the history, death and Resurrection of Jesus is the display in the created and sinful order of the eternal and unchanging relation of Father and Son within the Trinity” So that it is proper to say that the Cross is the Son’s eternal act of living for and from the Father as it appears through the reality of a broken creation. All of creation subsists between the Persons of the Trinity, created in the eternal begetting of the Son, redeemed in the Son’s eternal carrying out of the Father’s will.
This is rather like saying that just because we won the war doesn't mean that the Nazis are no longer in power and therefore Jews in Germany are still at risk of being gassed to death. That makes no sense at all.
I am not saying that sin has disappeared from the world, I am saying that sin has been given its death blow in Christ. Christ has departed, returned to the Father, and humanity is left with the commission of applying the work of Christ to human living- already assured of the victory which we alone can not secure. Christ died for all human beings, but this is not a passive salvation, we must claim the salvation which he won for us,
we must apply his life to ours. In traditional Catholic theology, this begins with the sacraments,
with the dispensation of grace which enables us to ever strive for holy living. With the sacrament of reconciliation, and the medicine of His Body and Blood, we can progressively model our selves in his image.
To use your own analogy, it would be exactly so that the Nazis are still strutting around in all the terrible grandeur of the Third Reich. But, for those of us who accept the great hope of the Cross, we know that their arrogance and abuse of power is in vain, that they have been robbed of all final victory.
This enables us with the courage to live as rebels.