Since slavery will so obviously be a topic of discussion I'll touch on it in this post and later respond directly to anything else. (Didn't want to ruin the beauty of the OP)
I came across this the other day, and though it's as simple a concept as can be, its vital in ones understanding. Three things to consider when reading the Bible:
What the Author wants to convey
What God wants to convey
What the times are when the Author wrote this
That pretty much sums up this..
Credited to the Catholic church
Contrary to popular belief the Bible was not written by God whispering into the ears of the human authors to write what he wanted written, but rather the Scriptures are inspired by God. The Holy Spirit guided the authors to be moved in such a way that their writings were of God.
Just as we participate in Godís ongoing creation (procreation) we also had a part in creating the Scriptures. God and his people have always worked side by side (Mary to bear Jesus, we create human life, the Scriptures, the prophets brought the message of God to Israel). The message that God wants conveyed is contained in the Scriptures, but the way it is conveyed was left up to the specific authors.
To that list I would like to add that the purpose of the Bible is to point the way to salvation and not reform society
For God did not send His Son into the world to condemn the world, but that the world through Him might be saved.
I can go into more detail (specifically about how God is blatantly against slavery (in the sense of physically abusive treatment), more specifically that practiced in recent years) but I think the above best briefly gives explanation enough to what you might cherry pick from the Bible regarding slavery, so that is all I'll say for now. If anything else is said on the subject that I feel the above doesn't clearly apply, I'll respond in more detail. But more than likely anything on this, or any subject, is made clear given you understand the above.
Accurate consideration of the Bible and reading scripture as a whole blatantly shows God has always deplored the cruel and abusive treatment of humans, his undying love for his creation.
Another topic of discussion will be that of a number of founders that supported/practiced slavery (even as far as using the Bible for justification), as if it lessens the greatness of their achievements. I'm fully equipped