Two key issues I tried to understand in Revelation. What did the author mean by the "Lord's day" in Rev 1:10? Some, like JWs, believe it referred to a vision of the apocalypse. Others think that John simply had a vision on a Sunday. Which sets up the whole thing rather differently. I didn't see this discussed in the essay.
Another is Rev 3:9. Who is John referring to as Jews here? Ethnic Jews or Christians as "spiritual Jews"? Does Revelation view the Jewish people as part of God's plan or as superseded by the Christian community of "spiritual" Jews?