You do well to consider the scriptures, and look to them. When studied with faith, they bring life and peace.
Leviticus 25:44-46 was not an endorsement of slavery, but an effort to limit it. This is clear if you read the surrounding verses. The scriptures serve as tutor for mankind, bringing him from a state of barbarity to a state of enlightenment. The main point of the passage you cite, when surrounding verses are considered, is that you are not to treat your fellow Hebrew (your neighbor) like that. Jesus then showed us that our neighbor is anyone who is around us. Mankind is tutored by God at a rate we can handle it.
I will have to address your points on capital punishment tomorrow. This morning I wold like to address your points on corporal punishment.
The slaves that you say Americans bought fair and square were mostly kidnapped, and as such do not compare with a 'bond servant" agreement.
You seem to think it fine for the State/Schools to beat on children but not OK for a Master that the parent has chosen to do the same. Wild children have to be disciplined for their own good and the good of society. On that we agree. What choice does the parent have about their government? In these days of complusory attendence laws what choice do they have in schools (unless they homeschool). At least they can pick their master.
I see the Bible's solution as less statist and more free than the socialist position that the state should have a monopoly on force. The more power parents (and their chosen masters have) to use force to discipline then the less force the state will need (and the less power it need have).
Perhaps you live among civilized, secular people who do not need a caning to stay out of trouble. Good for them, but you should not assume that the whole world is like them.
As for "slavery" being unchristian, it is in a way. Philemon is a good study on that, he was a run away slave and Paul teaches the next lesson on how "slaves" ought to be treated. The Bible tutors humanity to the final step.
Frederick Douglass was a former slave, and a CHristian. He observed that while the Bible permitted men to be masters it did not permit them to be bad ones. If he can content himself with that and still have faith in God, despite living as a slave, then Thatcherite is surely without excuse in his efforts to condemn his Maker.
Still waiting for your capital punishment points so I can respond to everything at once.
Nowhere does the Bible condemn slavery. Jesus himself endorsed the beating of slaves, even when they make an honest mistake so that they won't make it again. It may interest you to know that Darwin's most heated arguments with Captain Fitzroy (the fundamentalist Christian captain of the Beagle) were about slavery not biology. Darwin thought it to be a disgusting practice that demeaned the humanity of both slave and slaver, whilst Fitzroy supported it, claiming Biblical support.
I note that you fail to address the Biblical instruction to hold bond-servant's family hostage against the decision of a bond-servant to become a permanent slave. I also note that you fail to address biblical endorsement for sex-slavery.
The slaves that you say Americans bought fair and square were mostly kidnapped, and as such do not compare with a 'bond servant" agreement.
I have checked this with an academic historian who specialises in this subject and your statement is simply untrue. The overwhelming majority of slaves shipped from Africa to the New World were bought in African markets from African slave-holding chiefs. Sometimes these would be surplus population from the chief's tribe. Kidnapping in such huge numbers would have been dangerous, expensive, and difficult, compared with simply buying the slaves in African markets.
I do however find your "fair and square" phrase bewildering. Slavery disgusts me even when it is practiced in forms that are permitted by the bible, such as the legitimate purchase of non-Hebrews in slave markets. It is only you that should see the buying and selling of human beings as something that could be "fair and square".
I don't disagree in principal with corporal punishment as I have already stated. But I find the idea that a bond-master or slaver can be the sole arbiter of such punishment for bond-servants or slaves completely unnacceptable. Evidently you don't, so we are worlds apart on that one.
The Bible states that if such beatings result in death delayed by more than 24 hours from the punishment then no offence has occurred. This sounds like an invitation to make extremely violent bloody beatings to me, as long as the poor wretch clings to life for 24 hours. A sadist's charter. F Douglass may have said that the Bible doesn't require masters to be bad masters, but it doesn't seem to require them to be good either if the life of a slave is to be viewed so cheaply.
Still at least you seem to be true to your faith and your Holy Book on this one. Evidently you view slavery as an entirely acceptable human state.