O god o god o god
first let me set this straight.
"let he who has not sinned throw the first stone" is in only a few of the ancient manuscripts, so its pretty safe to assume it was added later, not that it matters though, because even if wasn't, the moral is that we shouldn't judge others because we are all worthy of death.
secondly, Mary WAS imperfect, otherwise she would have never gotten old and died. the reason Jesus did not inherit sin is because sin is only inherted through the father, and since Jesus's father was god, he didn't get sin.
and finally, the cross is an idol that the Egyptians used for a form of sex worship. and besides, it doesn't matter what jesus died on, what matters is that he died for us.