God to Jesus. I just condemned the human race. Now go die to save them.

[Drich]

Do you agree that the notion of substitutionary atonement is immoral

"Morality" is a variable and not an absolute standard. In essecne morality is whatever you want it to be. To judge this moral or immoral means nothing aside from taking a survey of the popular moral standard of your peers on this board. Morality is not the standard of righteousness you believe it to be.

and that God’s first principle of morality is hare/harm and that this would prevent him from demanding the death of his son?

To make this assertion based from the bible, one would have to ignore the rest of the bible that calls for the death/blood sacerfice of Christ.