Thank you for your careful research, Anna. I know this has been an issue of ongoing exploration for you.
Yes, it would be foolish to disregard the actions of some previous popes, but one must also keep in mind that these articles are referring to “encyclicals”, which are a very specific form of teaching/pastoral direction. The popes who have been corrupt, fortunately, had very little interest in teaching and guiding the flock of God, so did not offer such instruction. The most scandalous activities of popes have been confined to personal letters.
In answer to your question, I think each person will have to answer to God for acting in accord with their conscience. A well informed conscience will know the Scriptures and the Sacred Tradition, and therefore, be better able to discern in all things that they read, including papal encyclicals.
I think the concept of subjecting ourselves to authority is particularly difficult for Americans, since we have grown up in a culture of “don’t tread on me” and our national legacy is one that has been born out of rebellion.
We can speculate that the authority of the Apostles would have been easier for us to accept had we been part of those converted on the first Pentecost.