Questions about the Sealed Record

Ether 4:1 — Who translated the record from the Jaredite language into the Nephite language? See Mosiah 28:11–17.
Ether 4:1 — Why did King Mosiah not publish the record of the vision of the brother of Jared?
Ether 4:4–5 — Why did Moroni record the contents of the vision? What was he told to do with that record? Do we know, then, at least part of what the sealed portion of the plates of Mormon will contain? See also 2 Nephi 27:7–10 and Ether 3:25–26.
Ether 4:5–6 — Why might the Lord not yet have given us the full the record of this vision?
Ether 4:7, 15 — When will we receive this information? How can we be preparing for them to come forth?
Ether 4:16–17 — What does the coming forth of the Book of Mormon have to do with the revelations of John? How do we know that the revelations of John are indeed revelations from God? See 1 Nephi 14:18–27. What “work of the Lord” has “commenced upon all the face of the land”? What does all this have to do with the fulfilling of the Covenant?