I assume that you have written here about slavery as it was practiced in biblical antiquity. If so, you are partially correct, but only partially so.
Bond slavery, as you describe it, was practiced in ancient Israel and in both Jewish and gentile cultures of Jesus' day. A man could sell himself into slavery for a period of service. He could also sell members of his family into slavery. Bond slavery was a contract, and one could not freely walk away from it without penalties.
There's really no indication in the Parable of the Prodigal that he sold himself into slavery. He was probably working as a wage laborer. In that case, he truly was free to walk away.
There were however slaves who were bought and sold as well. Joseph's brothers, for instance, sold him as a slave to Ishmaelite traders (Gen 37.25-28). Beside bond slaves, there were also prisoner slaves taken in warfare. As I understand it, Philemon, under Roman law, had the option of punishing Onesimus harshly, having him branded with hot iron as a runaway or, possibly, exacting his life for theft.
Anyway, the Bible in both testaments approves of slavery, though the Scriptures places certain ethical restrictions on a master's treatment of his slaves. The Church has had to deal with this fact and has now, almost universally, condemned the practice of slavery in any form.
Which may or may not bear on how we read the Scriptures dealing with homosexual behavior.