By praying the Rosary,doesn't it seem that we are placing Mother Mary higher than God. since the 'Hail Mary' far outnumbers the 'Our Father'and 'Glory Be'?

Of course, our devotion must be to God the Father through Jesus Christ. However, the intercession of our Mother Mary is to take us to Jesus Christ and to God the Father. As John Paul II said,"To Jesus to Mary". Her intercession is not independent of Jesus Christ,like in the normal family the role of the mother is not separated(or should not be) from the one of the father.We venerate the  Virgin Mary (we don't adore her, we adore only God) because she is the Mother of God and she wants us to be with him. Besides, the prayer "Hail Mary" is almost all taken from the Gospel,which, along with the tradition of the Church, is the    source of Jesus Christ's teaching, and we glorify her for the (fruit of thine womb 'Jesus, who is the center of this prayer. Ask the Virgin  Mary to help you to know Jesus Christ better and  she will do it.         

During the season of Lent should we say the Sorrowful Mysteries every day?Or we can say all the mysteries like we normally do?

During Lent we can either recite only the Sorrowful Mysteries or as usual all the Mysteries.The Rosary is a private prayer,so there is no official rule from the Church about it. Personally, I prefer to say all the Mysteries as usual because we have to contemplate on the whole life of Jesus and not only on    one part of it. Even during Lent, we should meditate on his birth and other aspects of his life.The mystery of Jesus has to be concentrated in complete vision, with the help of all the mysteries and at all times of the year.

How are the Saints guide for Prayer?

The saints are our models for prayer by the example of their lives, their writings, and their intense prayer life.Even now in heaven, they contemplate God, praise him and constantly care for those whom they have left on earth. We can and should ask them to intercede for us and for the whole world.Their intercession is their most exalted service to God 's plan. In the communion of saints, throughout the history of the Church, there have developed different types of spiritualities that teach us how to live and to practice the way of prayer.[See CCC 2683-2684]

It is said in the Bible, do not worship or bow before any idols or images,then isn't taking a bow or kissing images going against the Word of God?

As for venerating, not worshipping, of idols and images, the coming of Christ made all the difference in how we worship God. When you read in the Old Testament, the promised people weren't supposed to worship idols because it inspired in them false ideas of what God looked like. For example, they worshipped Baal, an image of a bull and considered it as the god of fertility. The second council of Nicaea defined this matter by stating "Images aren't adored (worshipped in the strict sense), but they are honored, with the honor passing to the One represented. The same is true of images of the Saints, with the lesser honor due to them." This is like the love we express for our near and dear ones when we place photographs