As Psalm 45:3, supports Isaiah 9:6, that refers to the pre-incarnate Son.
You haven't even got your foot in the door finding support as you have been refuted every time you open your mouth.
Your "mighty one" doctrine is inconsistent. If being a mighty one means being God, then Nebuchadnezzar II, the king of Babylon at that time, is Lord God Almighty in your theology:
Ezekiel 31
11I will give it into the hand of
a mighty one of the nations. He shall surely deal with it as its wickedness deserves. I have cast it out.
Do you have even one supporting verse that Psalm 45:3 refers to King Solomon?
Given the context, it would only be king Solomon since David wrote so highly of him, had a foreign wife and daughters, etc. Are you trying to Psalm 45 is entirely about Jesus or just the parts you prviately decided are?
Psalm 45:2 says "You are the most handsome of the sons of men..."
But the Messianic prophecy of Isaiah 53:2 says of the coming Messiah: that he had "no beauty that we should desire him."
So right off the bat your interpretation contains a contradiction.
Jesus has His own throne that the Father testified as forever and ever.
Mat 19:28 And Jesus said to them, "Truly I say to you, that you who have followed Me, in the regeneration when the Son of Man will sit on His glorious throne, you also shall sit upon twelve thrones, judging the twelve tribes of Israel.
As previously stated, the only eternal throne Jesus was promised according to Scripture is the Davidic throne.
Luke 1
32He will be great and will be called the Son of the Most High. The Lord God will give Him the throne of His father David,
33and He will reign over the house of Jacob forever. His kingdom will never end!”
But the throne at the right hand of God is temporary (Hebrews 1:13, 1 Cor. 15)
Is this an acceptance that as Jesus sits in the throne of God, He also possessed God's nature?
If you think that believers will be given authority of God or as God just by sitting, I believe no one of sound mind would say that.
The debate always focus to Jesus, especially by the Arians.
No, I am showing you that your reasoning doesn't make any sense. Of course Jesus doesn't sit on the throne of God or else those who overcome would be sitting on the throne of God too.
I always based my belief of what the Bible say, not the fantasy of human mind.
You just made the words of the Almighty God the Father unbelievable Runningman. (Heb 1:8)
See above.