I'd accept what you are saying - except the reference to Christ's mother. Mary is not in heaven with Christ at all. That is one of the poisonous soul-destroying doctrines that is tantamount to idolatry. Mary is in the grave awaiting the resurrection of the just in Christ.
Christ taught everything the church needed to know through the books of the New Testament. The devil came along and taught the Catholics that Mary is their "Queen of Heaven", but didn't let on that he was installing an imaginary pagan Queen of Heaven instead.
Martin Luther went to Rome thinking that going there would sort him out and establish his faith in God so that he could stop believing that God hated him. instead, when seeing the priests with prostitutes, having fornication with nuns, having adultery with the wives of parishoners, and all the illegitimate children, he became even more disillusioned with the Church and fired up his desire to bring reforms to it. Then he discovered that the Bible told him he was justified by faith and not by works, and that revolutionised his view of God and what Christ did for him on the cross. And the rest is history. Then he realised that Mary the Queen of Heaven was an imaginary idol and the pope was the Anti-Christ.
They would know that an appearance of Mary would be a demonic vision and they would reject it out of hand, because they would have known that the real Mary is still in the grave awaiting the Last Day resurrection of believers.