Thank you for a copy and paste from your catechism. I've already studied it though to see what Catholics believe, and I am very careful when I choose my words. I do not say you "worship" Mary as God. But she is called Co-Redemtrix and Co-Mediatrix. This concept is unbiblical (as are many things). Sorry if you don't like what I am saying. I am trying to follow the rules of the thread and be respectful. But, in my estimation, having studied the subject at length, Catholicism's doctrine concerning Mary is unbiblical and I reject it.
It seemed to me you were confused as to Mary's role as Mediatrix. I guess you were not.
In any event, you must beleive that, at least when she wrote and compiled the Bible, Holy Mother Church was infallible.
Now, the difficulty arises in advancing an explanation as to how that once infallible Church failed that doesn't render nugatory the promises of Jesus about His Church He established.