I too have wondered if Paul was the twelfth. Certainly God chose him to be a preacher to the world. I have no doubt Matthias was also chosen of God to spread the gospel, but the Lord knew they would not readily accept Paul, and to his glory! The world was preached too. I'm not so certain that the other Apostles did not do what Christ asked, but the Bible doesn't say a lot about them really.
The church of today is based primarily upon pagan/catholic traditions. The traditions of the protestant churches of today are so inline with the church at Rome that the pope is not even worried about them. They are all good catholics! The traditions of man are vain and useless, designed to keep the word of God from being preached and lived. If men would rise up and seek the Lord with their whole hearts, if they would teach their children to fear God and love their neighbor, we would see the Kingdom of God. I cannot jugde the heart of man, only God can, but I know the Church of Christ is alive and well though the churches are dieing. God is doing a great work in the hearts of his people, to raise up a nation, holy unto him! Seek righteousness, seek the Kingdom, preach the word of God and understand "I will have mercy and not Sacrifice." if we would enter into his rest. I pray that the Lord would open our hearts and minds, that we would be the Church, the Body of Christ, in Spirit and in Turth.