Jesus is in the line of David and called a priest after the order of Mechizedek (an eternal priest).
I'm sorry, if you've studied the lineage of Jesus in Matthew and Luke, they contradict each other, and in either case descent from David is absent since he was born from a virgin. Mothers don't pass tribal lineage, nor does adoption help the case.
As I proved, Melkitzedek wasn't a High Priest. The High Priesthood only belongs to descendants of Aaron.
Jesus was the final sacrifice for sin.
This isn't true either as sacrifices continued after his death until 70 CE. Ezekiel 37 - 45 also show sin sacrifices during the future temple, of which the prince Messiah will present sin sacrifices for himself.
The levitical priesthood is no longer needed.
And yet Jeremiah 33:17-26 shows the Levitical priesthood and the Davidic king together with future sacrifices.
The old covenant of Moses has been replaced.
Wrong. Jeremiah 31:31-34 shows the same, renewed covenant written on the hearts and minds, not stone. It applies to the houses of Israel and Judah, not the church.
Jesus is the prophet Moses spoke of.
I doubt that. Moses never spoke of a god-man prophet, or one that fulfills ones obligation in the law.