Decipher the heavenly court scene (I)

Laura got married today. We were invited to a buffet dinner to celebrate with her. We haven't seen Bosco, her younger brother for a long time. He looked thin tonight.
The young couple is adorable. We wish them good luck, good health and abundant blessings from God and Our Lady.
A new scene appears in the heavenly court. In His right hand, God holds a scroll sealed with 7 seals (Revelation 5:1). An angel asks who is worthy to open the scroll (Revelation 5:2). John has long been an onlooker. But now, he is involved. He weeps much because no one in heaven, or on earth or under the earth is found worthy to open it (Revelation 5:3-4). Then one of the elders introduces the "Lion of Judah", the "Root of David" who can open it (Revelation 5:5). The readers should know that these titles refer to the Messiah.
The Root of David clearly refers to the Messiah. Isaiah tells us that the Messiah is an offspring of Jesse who was the father of David (Isaiah 11:1). Therefore, this Root of David is another way to say Messiah.
Now, let's turn to the Lion of Judah.
When Jacob (Israel) was old, he blessed his sons one by one. When it was Judah's turn, Israel described him as a young lion (Exodus 49:9). The Lion of Judah refers to a descendant of Judah, the Messiah.
However, Hosea the prophet makes an interesting prophecy. It says,
For I will be like a lion to Ephraim, and like a young lion to the house of Judah. I, even I, will rend and go away, I will carry off, and none shall rescue (Hosea 5:14).
Obviously, this lion refers to God. Therefore, the Lion of Judah can also mean God. The Messiah is not simply a human descendant of David, but God himself. There should be no doubt about the divinity of the Messiah.
Now this Messiah turns out to be a Lamb!
John the Baptist refers to Jesus as the Lamb of God who takes away the sins of the world (John 1:29, 36).
This Lamb doesn't look natural. It has seven horns and seven eyes (Revelation 5:6)! What a monster! John explains to the readers that the 7 eyes are the seven spirits of God. So, what can these seven spirits be?
Isaiah has the answer, but the answer is incomplete.
And the Spirit of the LORD shall rest upon him,
the spirit of wisdom and understanding,
the spirit of counsel and might,
the spirit of knowledge and the fear of the LORD.
And his delight shall be in the fear of the LORD (Isaiah 11:2-3a).
There are only six and the "fear of the Lord" repeats. This is a translation from the Masoretic Text. The Septuagint and the Vulgate has translated the first "fear of the Lord" into "piety". The story is long and interested readers may refer to this link.
So far, we have deciphered some obvious symbols. But what about the scroll, the seals? What do they mean? And what about the 4 living creatures and the 24 elders? Who do they represent?
When the Lamb took the scroll, the 4 living creatures and the 24 elders fall down before the Lamb, taking a golden harp and start singing the following song to praise the Lamb.
Worthy art thou to take the scroll and to open its seals, for thou wast slain and by thy blood didst ransom men for God from every tribe and tongue and people and nation, and hast made them a kingdom and priests to our God, and they shall reign on earth (Revelation 5:9b-10)
Then uncountable number of angels echo in return.
Worthy is the Lamb who was slain, to receive power and wealth and wisdom and might and honor and glory and blessing! (Revelation 5:12b)
Then every creature in heaven, on earth, under the earth, and in the sea and all therein say:
To him who sits upon the throne and to the Lamb be blessing and honor and glory and might for ever and ever! (Revelation 5:13b)
Then the 4 living creatures concluded with an Amen.
What do these choruses symbolize? What earthly events does this chorus scene refer to?
These are some of the questions we need to explore in the reading of Revelation.

The Lamb of God, You are worthy of our praises forever. We owe our life to You. I am grateful to You because You make our life worth redeeming. I pray that we may one day join this heavenly chorus to praise You. Amen.