I don't disagree- it is absolutely significant. I just think the leap from "Mary was a uniquely suited and gifted individual to serve as the worldy mother of God" to "prayers to Mary carry a unique weight and can compel God to take actions he otherwise would not take" is incredibly far. That isn't to say I think you are making the latter case- you've taken an exceptionally and refreshingly nuanced and patient approach to this discussion- that is just my perspective on the matter