Hi Walter, those are good questions generally speaking most protestants struggle with how the orthodox Christians venerate and honor the Mother of God and all the other saints. So your question is very much welcome because although it is based on a misunderstanding of what the orthodox believe and how they worship, we do understand and respect what you are guarding against, i. e. Idolatry and blasphemy against God. I say this with sincerity, I respect a serious seeker who is after the Truth. The First Commandment is a serious commandment its truth fundamental to our Faith. That there is only One God.
To address the specifics of your question now with the limited time I have right now, the miracles of the Blessed Virgin Mary refer not to St. Mary being God, but that by her hand God does many miraculous signs and wonders, due to the holiness of her life and the powerful favor her prayer has before her Son our Lord God and Savior Jesus Christ.
How do we even know of St.Mary ? We know the Blessed Virgin because of her son, in Israel there were many who were called Mary, none of them are remembered or honored like her, why? Because none of them are the Birth Giver of God in Flesh, She is the Mother of the Living, one given to us by Christ from the Cross. Behold thy mother! So there is incredible devoted Love for her in our hearts, in imitation of Christ her beloved Son, and our Lord we seek to obey and love her with the love of a child to his mother and she in turn always tells us to listen to Him as she has done in Canna. Her life the best example of obedience to God, humility, purity, and devotion to God, perseverance in suffering, Love unwavering, etc. we are all called to imitate because by imitating her we imitate Christ. She is the perfect example of what we are ALL called to become i.e. become God bearers!
The language used is not new, it is an Orthodox Tradition, to talk that way with the given understanding that all miracles are done by God, and that He does them by the hand of His Saints.
Everyone was filled with awe, and many wonders and miraculous signs were done by the apostles. Acts 2:43
The apostles performed many miraculous signs and wonders among the people. And all the believers used to meet together in Solomon's Colonnade. Acts 5:12
13Is any one of you in trouble? He should pray. Is anyone happy? Let him sing songs of praise. 14Is any one of you sick? He should call the elders of the church to pray over him and anoint him with oil in the name of the Lord. 15And the prayer offered in faith will make the sick person well; the Lord will raise him up. If he has sinned, he will be forgiven.16Therefore confess your sins to each other and pray for each other so that you may be healed. The prayer of a righteous man is powerful and effective.
17Elijah was a man just like us. He prayed earnestly that it would not rain, and it did not rain on the land for three and a half years. 18Again he prayed, and the heavens gave rain, and the earth produced its crops. James 5:13-18[/b]
There are multiple examples from scripture, we say David slayed Goliath, but it was God who did that, so many examples of the like, your mother carried you in her womb but it was God who carried you both. What becomes idolatry is when one ascribes adoration of the Creator to the created which says that the created is a creator. So if it was not for our adoration and worship of her son, we would not have known of her, all her glory steams from the glory of God who bestows glory and honor to his saints. Even more so to his mother. The glory of the seraphim, the cherubim, all the archangels is but a shadow compared to her glory she remains higher than all creation in her glory, and lower than God. As we love to call her “ metihete fetari , meli’elte fituran’’ / lower than God and higher than all creation/
So in giving honor to those deserving of honor, we honor God himself who is the source of their honor.
As to your second question, unless it is a case of lost in translation, all Glory is given to God who is Glorified in His Saints. When I say I thank Mary for this, I am not speaking in contradiction as if Mary is Christ, no, I am indicating by whose willing hands my God who helped me Chose to Act. The prayer of the saint is powerful, and God acts in cooperation with the human who is praying for whatever it is the human is praying according to God’s wisdom.so by the hand of St. Mary God’s healing power touches and heals our infirmity. If someone rescues you from being hit by a car you will say so and so saved me that day, but you are not saying that so and so is God, because in the end it is God who saves you. the spiritual life is as real to us the faithful who believe in the communion of the Saints, we love to say thank you to our saints for the love they show towards us, and we Love to thank God for the Loving Favor he shows towards his saints in granting their prayers on our behalf , saying: Glory be to God who is Glorified in His Saints. Amen.
So I would say Walter my brother, its wonderful you are asking questions, its one step to understanding the usage of these seemingly contradictory yet complimentary languages, and get used to what is a given assumption in the wordings of those phrases we use i.e. that God is at the heart of all things, so you may not get the wrong idea about the Orthodox who are quite zealous in defending and living out the First Commandment.
Hope that helped a bit , if not please continue to ask with specifics and God willing I will make time to reply the best I could as soon as I could.