Alex, you bring up a very important concept. The Orthodox Church, as you know, does not teach the "original sin" passed on to generations since Adam and Eve as guilt that has to be removed, but as a consequence of fallen human nature, made susceptible to sin, namely our mortality.
Thus, we Orthodox understand your argument as saying that Mary's susceptibility to sin was removed, as someone's susceptibility to catch a flu is removed by vaccinations. She was therefore made "immune" to sin and therefore could, by this act of God bestowed only to her as far as we know, to resists sin. Which would make her ontologically, as Koloktoronis said, different from the rest of us.
By the same reasoning, Mary, would have been made conceived immortal just as Eve was and her own death would suggest that she was not immaculate. Some Catholics firmly believe that she did not die, although I think the Latin Church remains officially silent on that issue.
The Orthodox, of course, teach that she died, since our mortality cannot be removed by baptism in this lifetime even if we are sinless.
The Orthodox Church, furthermore, teaches that Baptism is adoption into the Body of Christ, the Church. The baptized are sacramentally given a new life (a chance to be saved conditionally), by following Christ in the steps and teachings that are deposited in and uninterruptedly maintained by the living Church.
The Church does not guarantee our salvation. It only states that our chances of being saved are the greater because, relying on our nature alone, it is very unlikely that we will cleave to God, although we don't discount that with God everything is possible.
Someone might observe that the Orthodox recite in the Nicene Creed that baptism is for forgiveness of sins.
Baptism is forgiveness of sins actually committed. Obviously, a newborn infant hasn't (and couldn't have" consciously committed any sins, so this clearly does not apply to them, nor is there any inherited "guilt" in them.
Baptism is rebirth, as the prayer of the Orthodox Baptismal Service indicates by this silent prayer of the priest (obviously for females it is "her" instead of "him")
BTW, the infant, like the adults, is always upright (resurrected) during the actual baptism.
As can be seen, from the Orthodox point of view, the conceptual baptism hypothesized by the Latins in the case of our Most Holy Theotokos does not remove any "original sin."
Clearly, the Augustinian concept of "guilt" expressed in the "original sin" as understood by the West, is the very foundation of the dogma of Immaculate Conception. The Catholic Church, therefore, must make up its mind what the "original sin" entails: it is actual guilt, spot, macula, that is removed by Baptism, or is it a consequence of the original sin of our ancestral parents, expressed as corruptible human nature, prone to and attracted by sin, which, like a disease left unattended, will kill us.
I am afraid that bridging this gap is next to impossible, for it would require the West either to change its entire mindset drowned in Augustinian senseless error of "guilt" by birth.
please read the Cathoic Catechism, numbers 396 - 421. I do not think you have an adequate idea of what it is the Catholic Church Teaches
Great points. The Fall of Adam and Eve did something to mankind. Of that both East and West agree. It has always been interesting to me how the Eastern Churches handled it compared to the Western ones. A lot of the resultant differences between Catholics, Orthodox, and many Protestants came from St. Augustine. Which is sad, in that his views changed throughout his life and in many ways he's beliefs are not quite what any side makes him out to be.
I understand that. My point is that from the Catholic perspective, unless I misunderstand this difficult subject, there is no superhumanity because baptism removes the original sin.
We understand original sin as a macula, which of course, entails also concupiscense (disordered mind and weak will) and death. We do not, howwever, consider original sin as personal sin as it does not condemn to hell. We take the baptism clause in the Creed literally even when applied to children who are definitionally free from personal sin. These things may be ndeed difficult to bridge, but it is not fair to our understanding to say that Mary in our perspective is taking on superhuman qualities because of her immaculate conception. It is a bit like Protestants seeing someone kneeling in front of a statue of a saint and deciding "that man is an idolater". It ignores the native Catholic perspective and injects an innatural to us perspective in order to make the accusation.