Well #4 definetely is true, look at Matthew24:36. As for #2, doesn’t God the Son know everything? Isn’t He, as a person of the Trinity, a Divine being, omniscient? As for #3, *can *Jesus be wrong about anything? If He can, doesn’t that defeat the idea that he is God?
In #2 you say that the “Divine Nature” of Jesus is omniscient. Christ’s two natures are not seperable in that way. To say his divine nature does x or y is a turn of speech, like saying that the athlete in me wants to go to the gym, but the couch potato in me wants to stay home. I don’t really have two people in me battling things out. The athlete in me doesn’t know things that the couch potato in me does not.
We do not know exactly how Christ’s mind worked during the time of his earthly incarnation. He had a fully divine nature, and a fully human nature. It appears from Scripture that He was not omniscient during the Incarnation, because the Gospels tell us that He learned and grew in wisdom, see Luke 2:40, 52. We know that He is reported as saying things that are not true, and, as you point out, at times He appears to admit He doesn’t know everything.
The answer is that we don’t understand what it was like to be Jesus, be its likely that Jesus was not omniscient (in the way you use the word) during the Incarnation.
#3) God the Son cannot say anything that is untrue. This is clearly wrong. We would like to think that God would not say anything untrue, but He could. He could also decline to tell us certain things. Even more likely, we could misinterpret what He says so badly that it becomes untrue.
Your #4 relies on your statement that if Jesus were divine He must of been omniscient throughout the Incarnation, which I have discussed above. It also relies on interpreting the word “Son” in the passage to refer to Jesus as a member of the Trinity. Many theologians interpret it as a more symbolic statement meant to emphasize that not even the “sons of God,” which would include all Christians, know the end time. I don’t know, but neither interpretation is necessarily contradictory.
Of course, all of this presupposes that Matthew recorded what Jesus said accurately. That is a topic of its own.