2. The Aramaic word translated in this passage as "serve" is a word that applies only to deities and perhaps certain royalty of very high office. In some Bibles, it is translated as "worship" and while it is not the primary Aramaic word for worship, it is like the difference in English between worship and bowing down to someone in worshipful reverence. While it technically could be applied to a human, it is almost certain to be applied only to God. This is yet another reason why we believe that Jesus is God, because God doesn't give His glory to another god or to a mere mortal man and because we do in a sense worship Jesus, not as a man, but as the one God of Israel in human form.
3. We believe this text applies to Jesus because we know that God (Hashem, YHVH, etc.) is the ultimate and only true king over Israel, yet this man or manlike being is clearly in some sense a separate being from God, yet clearly is God and is king. A mere mortal man who comes with some endowment of power from God could not rule as king over Israel, could not do the things that are necessary to secure peace for the world and most definitely could not rule for all eternity. Only God is capable of these things, yet this being is clearly like man in some way. Jesus is a man on the outside, but in every way that matters, He is God. Not "a god" or one of many, but THE GOD of creation, of Abraham and of Israel. Only God could fulfill these roles, yet somehow God is clearly shown as being a human being in some sense.