Kyle I appreciate what you are trying to do here. The problem is that the Bible expresses many different attitudes towards slavery. The verse you cite, Exodus 21:16 was frequently used by abolitionists as well. The early Abolitionists were roundly condemned as heretics by many of the leading denominations in the United States at the time. In fact the Baptists, Methodists, and Presbyterians all split over whether the Bible allowed for slavery.
The Bible describes Solomon using slaves to build the Temple. It establishes distinctions between the treatment of Hebrew slaves and foreign slaves. Exodus 21 2–11 allows for temporary enslavement for Hebrew males but permanent for women, who it appears could be made wives of their owners or owners sons.
In Deuteronomy 15:12–17 female slaves are also to be released after seven years. Most scholars believe it was written several centuries after Exodus.
Neither Augustine or Aquinas believed that God forbade slavery and saw it as a result of a fall. They both accepted natural hierarchies among people based on age, gender, education, and social position. Once you accepted these natural hierarchies, slaves were seen as on the bottom rung.
My deeper concern is that even if your reading of that passage, which appears to speak mostly about kidnapping, is correct, that doesn’t change the fact that the American church was complicit in the expansion of slavery. If you have not read Frederick Douglass’ narrative I would encourage you too. He describes how one of his master’s became crueler to him after converting to a more evangelical form of Christianity. Southern preachers frequently told slaves to obey their masters in all circumstances and they quoted the Bible to do so.
I strongly believe that unless we as Christians both understand how the Bible has been used historically to support injustice and repented of those abuses then we will be incapable of serving as peace makers in these troubled times.
Peace