The text is perfectly relevant. You either believe in the Church as institution founded by Our Lord on the foundation of the Apostles or you don’t. We call it "cafeteria" religiosity when one picks and chooses different things to their own liking.
According to the Catholic faith, Pope John Paul II has exactly the same ecclesiastical authority as Popes St. Pius X, St. Peter the Apostle, and all other Popes in history. Criticizing the Pope is the same as criticizing Christ - Whoever listens to you listens to me. Whoever rejects you rejects me. And whoever rejects me rejects the one who sent me - Lk 10:16.
If you ever decide to become a Catholic they will enroll you in RCIA classes and explain it to you.
It is always proper for subordinates to criticize superiors if they stray from the truth--and this would include the Pope. The greatest Doctors of the Church have recognized this right. The Pope is not an absolute monarch. Nor is he a kind of angelic being. He is man subject to error, a steward of the faith only, not its creator. He may, indeed, be criticized--and it's high time we did so with this particular pontiff whose popularity as a celebrity has masked much of his radical agenda.