As I said, a read through of Matthew will answer your questions. I always find that when I'm having trouble knowing what someone meant to say after reading accounts of it, I try to find that person's actual words. It's amazing what a help that is.
Paul was not Jesus. Paul knew that better than anyone, and said so. Go see what Jesus said....then read Paul's letters.
I think you mentioned that you were a member of a Church of Christ congregation. When was the last time that the text of the day was from one of the Gospels, rather than from one of the Epistles?
I am not sure what you mean by "text of the day". However, the claim that has been thrown about on here about people who attend a church of Christ not paying attention to the Gospels is a absurd. There is regular teaching and preaching from all sections of the Word of God.
So you are saying that Paul was mistaken when he talked about the old law being ready to "vanish away"?