I don't have all the answers to those questions. I suspect they aren't answerable.
I simply note that the Bible puts a difference between Jesus' form before and after His ascension:
1John 3:2 Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when He shall appear, we shall be like Him; for we shall see Him as he is.
That speaks of how we will change. Not how Christ supposedly "changed".
I don't have all the answers either but I am willing to recognize facts that are uncomfortable to recognize. Facts that are essential to our understanding.
In the Incarnation, He was like us but we were not exactly like Him. This is the basic misunderstanding that Unitarians use to deny the Divinity of Christ. 'Like" never means "IDENTICAL". It just means "similar". Just like synonyms are similar but very seldom identical in meaning. Which is part of the reason why other words exist at all.
Unitarians insist that Christ must be exactly like us. He was never exactly like us. He was similar. Never exactly like us. There are many reason why I say this and make distinctions that must be recognized. Examples
1. Christ did not know what it was to sin personally. I know what it is to sin personally and to be personally responsible for my sin. Christ experiencing the results of my sin is enough. He didn't have to personally sin to experience my own guilt.
2. Christ did not see corruption when He died like I will see corruption when I die. The change you reference in 1 John 3:2 is a reference to how I need to change. Not how Christ needed to change.
As much as Unitarians want Christ to be just like them, He wasn't. I refuse to bring Christ fully down to my rank/level when He was so much better than I am. God Incarnate is such a meaningful aspect of my theology.
I believe I have a mature understanding of these topics. I'm not a novice or unlearned in this.
There is no context wherein the Person of Jesus Christ isn't superior to us in all ways. Even in the Incarnation.
Mat 23:10 Neither be you called masters: for one is your Master, even Christ.
There is no lack of a context of merit when it comes to the work of Jesus Christ. He in all ways merited His position. Such requires Divinity in all things.