Thanks for your thoughts. According to the Bible, Jesus came to bring the good news of the Gospel first to the lost sheep of Israel. Daniel prophesies Isaiah’s prophecy of a promised Messiah was fulfilled with Jesus’s Birth. Now Salvation was for the Jews first, as Jesus himself said in the Gospels. Because, Jesus was born as a Jew so, the salvation is from a Jew (God’s chosen people) for the Jews to bring them back to the one true God through their promised King, the Anointed One, or the Messiah. Now the twist happens, Jews completely rejects the authorship and Messiahship of Jesus, so the Salvation goes to the Gentiles. This was the very beginning plan of God to bring the house of Ephraim and Judah together (you can find this in Jeremiah). Remmber, Joseph married an Egyptian priest’s daughter (2 sons, Ephirah and Mannash) were ingrafted Jews, through Joseph (a Jew by Birth). The same happened with Ruth (a Moabite) married to Boaz (by birth Jew)= David’s Royal bloodline (Jesus Christ’s decedents). Jesus himself said, I came not to abolish anything, but to fulfill the law. With Jesus Christ coming 2000 years ago, Judaism is technically complete. Christianity begins with one being a follower of Christ, regardless of being a Jew or Gentile. In my thoughts, Christianity is not an extension of Judaism, because then we would have to follow all the Jewish customs and most importantly the Holy Law. Apostle Paul makes a strong argument regarding these concepts in the book of Romans and many other epistles, regarding the significance of Grace. According to his words, “the Law kills, the Word gives life”. There were in ancient times, many just practices, where the new convert Jews wanted still to follow all the Jewish customs, including the significance of circumcision. Apostle, Paul rebukes the Church, teach them the right teaching, and warns anyone to fall away from what He or the other Apostles taught. He also engages with Peter in Acts regarding the same issue. Today, we have Messianic Jews, who follow most of the Jewish customs, but according to the bible, they are not to do that, so I am not sure, how they are following Christ fully, and I would say still in bondage of the law. Apostle, Paul says, Law is such Holy, that if we break one, we break all, thus there is no escape from the sin under Law, except through the shed blood of Jesus, the forgiveness of sins once and for all, remission into new Life of Grace, which is not a license to Sin. Hope this helps out.
Again going back to the Canaanites, They belong to the descended of Esau, but lived in wickedness and followed terrible practices. God gave them ample time to repent and turn away from Sin. For example, if we plant a tree (flower or fruit-bearing or even for wood), nourish it, allow it to grow, what do you naturally expect from the tree? Fruits, good appearance, healthy look, shade, wood, etc. But if it does not produce as excepted, we can wait and watch how it does, in few more years. Now, at last, if it’s a burden, does not give anything of value, what would you do? Cut it out, even try to get it out from the stump, and plant a new tree or do something useful from the land or ground piece. Immagine the same with Canaanites. God is the giver and taker of life, our standard of morality and justice comes from God himself, thus to Him, they had enough time to turn from sin and live a Holy life. Hope this provides some clear understanding.
Regarding Esther, you are right Haman was dead, but the law that he fastly created could not be revoked due to the King’s seal. Persian kings use to keep annal of Records and laws, by which they use to make the decision, instead of making their own decision. Later, when Esther request the king to cancel the annihilation of the Jews, the King could not do it. Rather, he thought of a wonderful idea and gave the authority to Esther and Mordecai, to come up with a solution, without revoking the original declaration. Now, citizens or slaves of any nation have any right, but they all are under the authority (first God, then king or rulers). If a ruler decides that citizens have to pay tax to the king, or produce etc (they have to do it). If the king decides, slaves’ children will be killed, the solider would execute that proclamation, and slaves have no right (you can find this example, with Joseph, during the time of Jesus birth, Moses birth ) etc. So Esther and Mordecai, bring a new law that would allow the Jews to defend themself from their attackers. You are right, slaves did not have any right in the past, they often served once household, or kings, rulers, etc. Now during the biblical time, Jews also had slaves but they were part of the family, not like the Egyptian slavery of the Jews for 500 years. Regarding intermarriage, that was just to show why in the first place, the problem of Geonicde happened with respect to Biblical timelines. Jews by the law were not to intermarry other cultures (Esau was the first one to do that) and several new wicked cultures came from them, which was not God’s plan. Now, people should not take the example of the Bible to kills other communities, that is not God’s intention. What happened in the Bible is God’s divine plans for His chosen people, to fulfill His promises made to Abraham and to bring Messiah into the world.