I find your candid statement rare, and i basically concur in principle, in the sense that i do not see an assuredly infallible magisterium as being necessary for truth to be preserved. But God raises up men from without the formal magisterium if needed, to reprove such leaders who depart from the faith and cause souls to err. (Is. 9:16) And which i have often commented on, and i have a headache from weak glasses and its too late to add much more.
Maybe you haven't spent enough time with Catholics. Grumbling about bishops or the loose cannons in Vatican City is a major recreational activity. Popes and bishops are mighty thick on the ground in Dante's Inferno.
One of history's great Lay Dominicans, Catherine of Siena, had no reticence in confronting the Pope in Avignon and, in urgent but respectful language, telling him to man up and return to Rome. I do not see this sort of thing as contradicting the idea of the Magisterium or implying any disobedience or disloyalty.
But God raises up men from without the formal magisterium if needed, ...
I wonder if you may be over-concretizing the Magisterium. Catherine of Siena was not a cleric , but she is a "doctor of the Church." With respect to the Magisterium it doesn't get more 'formal' than that.
I got new glasses and they're great! I hope you can get some that are right for you. I don't HAVE headaches, I AM a headache!