I mostly agree with it. I would clarify that Protestants are (usually) Christian, but yes, I believe that the Catholic church is the one, true Church. As Pope Benny infamously said, Protestant churches are substantially defective. He backtracked because the statement could lead to misleading presumptions, but he never said it was untrue. They are defective in that, absent valid sacraments, they can offer no guarantee of salvation, and that defect is one of their substance.
With all due respect to you, and to Pope " Benny" (whom I admire), therein is the rub. Protestants (evangelical, fundamentalist "Bible-thumping" Protestants) preach salvation through grace alone, apart from works, by means of faith in the finished work of Christ on the cross. Sacraments excluded. Now, I'll fully admit that I don't completely understand the significance or substance of the sacraments, but where they function as hoops to jump through as a "faith-plus" kind of proposition ("faith-plus-sacraments") as a means to salvation, that's probably the biggest dividing line between Protestants and Catholics. I guess I'd have to say I'm Protestant primarily because I agree with Luther's expounding on the teachings of salvation through faith he discovered when he really got into the book of Romans (and Galatians, and Colossians). Grace alone, by faith alone, through Christ alone. I can appreciate it if the Catholic Church teaches something else, but I cannot accept that. I do not see the sacraments as imperative in the teachings of Christ, nor in the teachings of the apostles, hence, in the teaching of scripture.