Mary doesn't "lead us" to Jesus.
I beg to differ.
This is completely without support anywhere in Scripture and is solely an invention of the Church (and it's a late, medieval invention, too, it has no basis in the tradition or practice the early Church).
It's not any more "medieval" than the Council of Nicea is "medieval."
Just as Eve, wife of Adam, yet still a virgin, became by her disobedience the cause of death for herself and the whole human race, so Mary, too, espoused yet a Virgin, became by her obedience the cause of salvation for herself and the whole human race.... And so it was that the knot of Eve's disobedience was loosed by Mary's obedience. For what the virgin Eve bound fast by her refusal to believe, this the Virgin Mary unbound by her belief.
-St. Irenaeus of Lyon (d. 202)
From Saint Ephrem
Thou alone, O Lord and Thy mother are they who in every respect are wholly beautiful; for there is no spot in Thee, O Lord, nor any stain in Thy mother.
-St. Ephrem (d. 373)
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.