"... in order to keep Mary as a Co-Redeemer of the faith..."
It is a minor point given the great gap between Protestant and Orthodox belief (and the relative closeness of Orthodox and Catholic beliefs from a Protestant point of view), but the title of co-Redemptrix is not one that the Orthodox Church gives to the Theotokos.
A difference between our approaches can be seen in our "basic" prayers to Mary, and the centrality of said prayers.
RC: Hail Mary, full of grace.
The Lord is with thee.
Blessed art thou amongst women,
and blessed is the fruit of thy womb, Jesus.
Holy Mary, Mother of God,
pray for us sinners,
now and at the hour of our death.
Amen.
Orthodox:
Rejoice, O Virgin Theotokos (birthgiver of God),
Mary full of grace, the Lord is with thee.
Blessed art thou among women,
and blessed is the Fruit of thy womb,
for thou hast borne Christ, the Savior of our souls.
While the "Hail, Mary" is the most common prayer in Catholic piety due to its repetition in the Rosary, overwhelmingly the most common prayer in Orthodox piety is the Jesus Prayer:
"Lord Jesus Christ, Son of God, have mercy on me a sinner." (or the common briefer version: "Lord Jesus Christ have mercy on me.")
Again, none of this is perhaps very significant, but for completeness I wanted to point it out.
I think I say both about equally, perhaps the Jesus prayer more.
I guess I'm Roman Orthodox.
:)
Whether or not the Orthodox gives the specific title of "co-Redemptrix" to Mary is immaterial. There is little doubt that she is elevated to the "mother of God" status and an object of veneration (worship). This is a "poor" tradition.
I find the Jesus prayer far more in line with what I believe the apostles would pray than the basic prayer to Mary. In fact, I cannot imagine for one moment Paul, Peter, James or John asking Mary to pray to our Lord Jesus asking forgiveness for their sins. But I suppose I'll hear some "traditional" story written in 852AD to that effect.