As to Hebrews 1:8 and all the other quotes contained in Hebrews 1 from the OT, have you read the OT verses in there full context? If your answer is no, then you have accepted an interpretation of Hebrews 1 based on the traditions of men and not by the use of every word that proceeds from the mouth of God.
Saul, David, Solomon and 45 other men were kings over Judah/Israel. So if I use your logic all those kings are also God. Scripture does not allude to the deity of Jesus Christ unless you interpret "one God, the Father", and "only true God" as lies perpetrated by Jesus and Paul to deceive the gullible.
My Unitarian belief is supported by the entire word of God, which you cannot say for the Trinity. Also since you have not addressed the fact the Son is not omniscient, which is an attribute of God you are demonstrating the weakness of your position.
As to why some of the Jews equated Jesus' statement that He is the Son of God as Jesus saying He is equal with God, you refuse to address how Jews view the status of the elder son. However, when the Jews accused Jesus of claiming equality with God, He corrected them by quoting the OT statement that the Jews were gods and then Jesus said He was the Son of God. Jesus never claimed to be God, the apostles never wrote that Jesus is God. Scripture does not tell us Jesus is God. Men have interpreted a select few verses to mean Jesus is God, but in order to maintain this stance you have to ignore all the unequivacle statements that there is but one God, the Father.
Now, when are you going to comment on this: But What About John 1:1?