I need to be clear as well, SG, because it comes up a lot in these conversations.
I know and fully acknowledge that neither you or MM believe Christ actually sinned.
My disagreement is not that Christ came in the likeness of sinful flesh, that God spared not His only Son, or that it was God's predetermined plan that Christ suffer death on the cross. I agree it was God's will "to crush Him" and that Christ bore our sins.
The issue, however, is whether Satan is a type of Christ. You see, I believe Christ "becoming sin" points to the cross in that it is defined by those passages you mention. He bore our sin, God laid our iniquities on Him, and He suffered the cross so that by His stripes we are healed.
But that does not mean I believe Satan is a type of Christ. I believe an improper emphasis on "made sin" led both of you to an unbiblical conclusion.