What is the significance of opening the Bible to a different page for each Degree? What pages should be used for alternative sacred scriptures?

There is no particular symbolic meaning associated with opening the Bible to the scripture lesson of the Degree in which the Lodge is working. Indeed, plenty of Masonic Ritual workings do not include this practice. We do this in New York for entirely practical purposes: The Chaplain stands at the west side of the Altar facing East when he delivers the scripture lessons in the various Degree Rituals, which makes it possible for him to read the scripture lesson directly from the open Bible in front of him. Because this practical advantage cannot be obtained from alternative sacred scriptures, they may be opened to any page the Lodge or candidate chooses.