Why do you place more importance on repentance and confession than baptism?
LOL. Your ears to God's lips. 8~)
The "thief on the cross" argument is not a valid argument against baptism. Christ had not yet died and risen from the dead, so the church was not yet established. Also, there is no guarantee the thief had not been baptized by John at some point, since many people in that region had done just that. The point is that Jesus had the ability to forgive his sins, and He did just that. We are under a new covenant, and baptism is an essential part of that covenant.
You do place more importance on repentance and confession than baptism, because you place both of them before salvation, but you place baptism after salvation. That is not what the Lord taught, and that is not what His apostles taught.
I agree we are one body, and that one body had one faith and one baptism. A faith that leads to salvation before baptism is different from a faith that leads to salvation after baptism, so it is not one faith.
I agree we don't decide who receives or deserves His mercy. He does, and He has made it known through His Word. His Word teaches that belief, repentance, confession, and baptism all come before salvation.