Yes! The rosary is called the “bible in your pocket” for a reason. Each mystery helps you meditate on the life of Christ. Though the word “rosary” does not appear in the bible, the contents of what the rosary is all over scripture.

“Hail Mary full of grace” (Luke 1:28). “Blessed are you among women” (Luke 1:42) “Our Father” (Mathew 6:9-13)

Short answer: It was given to Saint Dominic by the Blessed Virgin Mary. Long answer: The rosary we are most familiar with today has been forged like a sword. First the Angel Gabriel said the words “Hail Mary full of grace the Lord is with thee”. Hundreds of years later monks had the practice of praying the entire psalms and used pebbles to keep track of the 150 psalms. It later developed into a bead and string prayer known as the “Angelic Psalter”. By the 1200s Saint Dominic was given the joyful, sorrowful, and glorious mystery. Check out this video for greater details: https://youtu.be/dwVdYXyxln0?si=Q0hJz0D0D5c8xL-2

No.

Praying the joyful, sorrowful, and glorious mysteries. Each mystery consists of": 1 - “Our Father” 10 - “Hail Mary” 1 - “Glory be to the Father” Saint Louis de Montfort mentions that praying 1 mystery is what is expected of children. Praying all 3 mysteries makes 1 full rosary. (Today we also have the luminous mysteries. This would be considered an extra to the original).

Yes.

You will increased your devotion to Our Lord Jesus Christ. The Blessed Virgin Mary has made promises of many graces to those that pray the rosary. For example: - The Rosary shall be a powerful armor against hell. It will destroy vice, decrease sin, and defeat heresies. - Those who have a true devotion to the Rosary shall not die without the sacraments of the Church. - The faithful children of the Rosary shall merit a high degree of glory in heaven.

https://dominicanfriars.org/the-15-promises-of-the-rosary/