If 2Pet 1:19,Rv 2:28, and Rev 22:16 reckons Jesus is the “Bright Morning Star” (even said so Himself) then how should we understand Isaiah 14:12?
First of all, 2 Peter 1:19 does not call Jesus the “Bright and Morning Star.” I am not sure this changes your question much, but thought I would mention it. It might possibly be a reference to Jesus, but this is a bit speculative. Peter tells his hearers that they should pay careful attention to “the word of the prophets made more certain.” Let me suggest a couple of possibilities for what “the word of the prophets made more certain” my refer to. Perhaps he means that we should pay more careful attention to the Old Testament, or perhaps to the gospel message, which is the fulfillment of the Old Testament prophets, or he might mean that we should pay careful attention to the gospel message, which is contained in “the word of the prophets.” He says that we should pay careful attention to this “word of the prophets” as we would to a light shining in a dark place. He says that we should pay attention to it until the morning star rises in our hearts. What does this means? It might possibly mean that we should pay attention to until Jesus comes back. It might mean that we should pay attention to it until our life ends, after which we will see the morning star. It is really hard to be sure what Peter means. I suppose what he means is that we should pay really close attention to the message!!!
Nubmers 24:17 might be helpful. This is clearly a messianic prophecy, referring to the Messiah as ”a star [that] will come out of Jacob” This does not call Jesus a bright and Morning Star, but it might be relevant. Then, as you mention, there is Revelation 22:16. This clearly has Jesus calling himself “the bright and Morning Star.
So, now we know that “the bright and Morning Star” is used as a reference to Jesus, but the phrase morning star may or may not be a reference to Jesus. Now, let us go to Isaiah 14:12. This is a description of an oppressor of Israel–Babylon (Isaiah 14:4). In Isaiah 14:2, God says about Babylon, “How you have fallen from heaven, O morning star, son of the dawn. You have been cast down to the earth, you who once laid low the nations. You said in your heart, Í will ascend to the heaven; I will raise my throne above the stars of God.” I understand that many believe that this prophecy is about Satan, but I do not agree with this interpretation. God told Isaiah that it was about Babylon (14:4 and elsewhere). The context and the information is consistent with Babylon. What God seems to be saying is that Babylon, in its pride, thought itself great enough to ascend to heaven–to be like a god. God is telling them that their pride will be thrown down and that Babylon will be humbled. I believe that the reference to the “morning star” probably means that Babylon felt it was a kind of god or angel or heavenly power. In any case, even if this is a reference to Satan (I believe almost certainly that it is not!), this passage is not calling Babylon “the bright and Morning Star.”
In summary, from Revelation we can conclude that “the bright and Morning Star” is a reference to Jesus, but 2 Peter 1:19 might not be a reference to Jesus and Isaiah 14:12 definitely is not a reference to the bright and Morning Star or to Jesus.