“And if he will not hear them: tell the church. And if he will not hear the church, let him be to thee as the heathen and publican (Mt 18:17)”
This verse is about arbitration in the local church between two believers. It is about the response to the arbitration by each of the two parties. It not about a “pope”.
Wrong.
Matthew 16:19: "Whatsoever thou shalt bind on earth shall be bound in heaven, and whatsoever thou shalt loose on earth shall be loosed in heaven."
"Binding" and "loosing" were technical rabbinical terms, which meant to "forbid" and 'permit" with reference to the interpretation of the law and, secondarily, to "condemn," "place under the ban" or "acquit."
Thus St. Peter and the popes are given the authority to determine the rules for doctrine and life by virtue of revelation and the Spirit's leading (see Jn 16:13), as well as to demand obedience from the Church. "Binding and loosing" represent the legislative and judicial powers of the papacy and the bishops (Mt 18:17-18; Jn 20:23). St. Peter, however, is the only apostle who receives these powers by name and in the singular, making him pre-eminent.[1]
[1] Armstrong, D. (1998). The Pre-Eminence of St. Peter. Retrieved from http://www.ewtn.com/library/SCRIPTUR/50PROOFS.TXT