I am familiar with all of those verses. Perhaps you misunderstood me. The fear message used is that Catholics are going to hell merely for being Catholic. No other reason. No personal holiness or prayer life can possibly save them. Jesus has rejected them for no other reason. That falls way short. And, my personal favorite, no one who claims Jesus (and btw, Catholics regularly affirm their love for and faith in Jesus), regardless of any evil they do, whenever they do the evil, will go to hell. Jesus clearly warns each of us through the New Testament to avoid sin, to live as He taught us, by the examples He gave us. These verses do not say one is going to hell because one belongs to any Church that praises God and follows the teachings of His Son, Jesus. And following them is accepting them.
They believe that it's 'Jesus only', therefore, when they see all the 'tradition' being practiced they assume that all those things are 'needed' as well.