Your post is very good. My problem with many of the posters on this site is not that they disagree with Catholics, or even that some left the RCC. We all have to go where we think the Holy Spirit is leading us. My problem with many of the posters on this site, and especially former Catholics is precisely--that they seem to have this "chip" on their shoulder. It is one thing to respectfully discuss and debate differences, another thing to do it with a chip on one's shoulder. I guess that is what I mean by the term "Bible thumper." A Bible thumper is one who evangelizes with a chip on their shoulder.
The fact is-----in some ways, all arguments are an appeal to authority. When the Protestants appeal to the Scriptures, they aren't really appealing to the Scriptures, what they are doing is appealing to an interpretation of the Scriptures that is based on what they were taught by their ministers, teachers, scholars, etc. Protestants deny they are doing this, instead claiming to go by the Holy Spirt of course.
Now, Catholics freely admit that any appeal to the Scriptures in the Catholic Church, is really an appeal to an interpretation based on the teachings of the Faith. For Catholics, the Bible is the Divine text book of the Faith, the Church the divinely authorized teacher. Because the Church is the divinely authorized teacher of the Scriptures, the idea that Church teaching is not evidence that something is scriptural and revealed---is sort of oxymoronic for the Catholic. If the Church is the divinely authorized teacher of the Scriptures, then who would know better than the very Church itself whether or not something is scriptural and revealed? Hence, the "Sola Roma Ecclesia" accusation is simply absurd. If we aren't supposed to look to the Church to teach us the Scriptures, who should we look to? The government?
Thus, everything is ultimately an appeal to authority. The question is--which authority is divinely authorized? Catholics see this as the RCC, Protestants do not.