Jehovah is pronunciation that some German Biblical scholars thought that the Name of God would have been pronounced like. Even saying Yaweh, as it is spelled is not exact. The text of the Old Testament in Hebrew does not have vowels, and the Name is held so holy that an observant Jew will not pronounce it.
As to the History of how the Biblical Canon was decided on by the Catholic Church, with the guidance of the Holy Spirit, there are any number of websites that discuss the history. And when and why most Protestants edited out the deuterocanonicals is a complex history.
One of the problems with arguing the subject with Protestants is they have been taught that the Catholic Church “Added” the Deuterocanonicals at the Council of Trent. They truly believe the distorted history they have been taught, and much like the Iglesia Ni Christo, are taught that the Catholic Church had supressed the truth. For a Catholic exlanation on the Canon of Scripture, read this website.