The physical interaction between holiness and fallen flesh is a mystery still. Why would God have Moses remove his shoes? Something akin to conductivity?

Chris likely needed nothing to purify the vessel but his very arrival. It seems John the Fetus felt the same way. As I see it, Jesus' presence can purify in such an overpowering way that it sent demons shrieking in fear. He wasn't in need of anything the Spirit couldn't accomplish at the time of conception. With that said, she was "favored." It does not say she had some special purity.

There are two occasions in which Christ purposefully detracts from that line of thinking, the one I mentioned, where Mary and the siblings were at the door, the other this:

And it came to pass, as he spake these things, a certain woman of the company lifted up her voice, and said unto him, Blessed [is] the womb that bare thee, and the paps which thou hast sucked. But he said, Yea rather, blessed [are] they that hear the word of God, and keep it. [Luk 11:27-28 KJV]

I appreciate that there is extra-biblical revelation, but if it doesn't jive, we have a duty to question it. My concern is that if Christ himself would lead us to not focus on Mary quite so much, why is she so highly focused on in any tradition that purports to follow Christ? You regard her as an obedient vessel, as do I. Genetically and prophetically she was the culmination of Israel as "the Woman" in revelations up to the point of the birth, but spiritually, the Woman lives on. She is a part of what God is doing, not a part of God. This picture is at odds with the way that the term "Mother of God" verbally paints her as somehow prior to (and therefor superior to) God himself, in a term we use for the Almighty, who is self-existent, eternal and above all. Sadly, there are those who take it that way, too. Praying to her adds to the confusion. That's another rant :)