Read the post. It’s all official Catholic doctrine and reiterated by a number of popes.
Hence they could not be saved who, knowing that the Catholic Church was founded as necessary by God through Christ, would refuse either to enter it or to remain in it.
As I said earlier, some Protestants may indeed be saved. It will be because they are, however imperfectly, "in" the Church.
So all of your citations are irrelevant.