I think I explained the benefits of the Rosary Prayer quite clearly in the post you are responding to. Still, if you have a question, I will be glad to answer.
We Catholics agree with the scripture you cited, as always. When one recites the rosary, or any other prayer, he should have his mind on it, understand it deeply, and not do it for a vain reason.
Prayers to Mary are not only a waste of time, but an affront to the Triune God who alone hears our prayers.