Q. 1. Is the common way of administering the Sacrament of Baptism in the Roman Catholic Rite by pouring only?
A. 1.On the matter of the Sacrament of Baptism, # 1239 of the Catechism of the Catholic Church states: "Baptism is performed in the most expressive way by triple immersion in the baptismal water. However, from ancient times it has also been able to be conferred by pouring the water three times over the candidate's head." That answers your question. Baptism by pouring is one of the two approved ways to administer the Sacrament of Baptism in the Catholic Church.
It should be noted that sprinkling is not the same as pouring. There is a difference between sprinkling salt on something versus pouring water over it. You certainly would not pour salt over your food.
The pouring of water during the Sacrament of Baptism can be done from the hand, with an object such as a shell, or a jug. This excludes sprinkling drops from one's fingers.
The 1917 Code of Canon Law did permit sprinkling as a licit (legal) manner of baptizing. The 1983 Code of Canon Law states that "Baptism is to be conferred either by immersion or by pouring." Some Church experts indicate that sprinkling is still a valid way of administering the Sacrament of Baptim, but it is illicit (illegal) and therefore it should not be used. That means that although sprinkling during the Sacrament of Baptism would be valid, it is not the Catholic Church approved way of doing it.