The extreme veneration of Mary (which I do believe crosses the line into idolatry and real worship for many Catholics) was a progressive practice in the Church. It started with the reverence and honor from the early Christians (as those two quotes you included, show) and it increased and expanded over the centuries until it became outright worship for many.
Look at some of the more primitive, third world countries, where there is a less educated population. Places like Mexico, or Africa, or remote regions of Asia. In Mexico, for instance, they carry around statues of Mary on "biers", surrounded by candles, and flowers, etc. You tell me how that is any different than worshiping her. Try and tell me with a straight face that the poor and uneducated population can even tell the difference. Millions are engaging in idolatry, probably, because of a misguided tradition that developed within the Church.
Sorry, but that's my opinion.
This:
Mary, too, espoused yet a Virgin, became by her obedience the cause of salvation for herself and the whole human race
You're completely wrong, Boagenes, and not even Luther would agree with you.
Your argument is made moot by the fact that descendants of Italian immigrants here in the United States (and people in Italy to this day) do the same, not just with Mary, but with other saints. This is also done in Malta, Poland, and the Catholic parts of Germany. The veneration (not worship) of images was defended by St. John Damascene, a man subject to the cruel reign of Muslims and their iconoclasm, and his view was upheld by both the Western (Catholic) and Eastern (Catholic and Orthodox) Churches by the Second Council of Nicea in 787.