You will notice that all of the patristic citations that I have offered to date come from Orthodox sources. [snip]I am only presenting these Orthodox sources to counter the accusation that the Catholic Church teaches heresy when she teaches that the Mother of God is mediatrix.
Except no one is disputing that she is a
mediator. What has been disputed is that she is the 'mediator of all graces'. And 'mediator' does not equal 'mediator of all graces' no matter how many of the thousands of Patristic statements about her being a mediator you post.
I also notice that you have never gone back to address the St. Maximus' quote, the one that is the clearest expositional teaching on this thread (as opposed to the poetic language of devotionals referring to her unique role as the Birthgiver of Christ, the savior and unique mediator between God and man), and which quite clearly precludes any attempt to claim that 'all Grace' comes through the Theotokos.