So regarding Christ being "made" sin for us, we know from Scripture that this means he took all sin upon himself as the "lamb of God" and made propitiation for us all. Paul was hardly the only prophet who described him in this way. See for example:
Hebrews 9:28
so Christ was sacrificed once to take away the sins of many people; and he will appear a second time, not to bear sin, but to bring salvation to those who are waiting for him.
or
Hebrews 10:10
And by that will, we have been made holy through the sacrifice of the body of Jesus Christ once for all.
or
1 Peter 2:24
He himself bore our sins in his body on the tree, so that we might die to sins and live for righteousness; by his wounds you have been healed.
I snuck those verses in from Hebrews since IIRC, y'all have disputed that Paul was the author. I can show many, many more verses that say the same thing but I am not convinced it would be good enough. Minds that have already been made up cannot usually open to receive another view. I hope it has not been hardened that far and that God's word can still be illuminated.
You need to read the Gospels, especially Luke. the idea that Christ died for others' sins doe snot make him sin. Christ remains innocent and sinless. His death becomes ultimate injustice.
To suggest that Christ "bore our sins in his body" (1 Petr 2:24) is contrary to the Gospel accounts and the Christian belief that Jesus was sinless to the end, and died an innocent man.