I am a Biblical literalist (I guess you could call me that.)
I disagree with his theology that applies the Old Testament law to modern day Christians. Therefore, I think slavery is completely 100% wrong. And I don't think Old Testament slavery is analogous to slavery in the USA.
However.
In the time it occurred, it was very common to makes slaves of the nations you conquered. I believe at times God commanded Israel to completely wipe out and kill all people of the enemy forces. It is not up to me to compare God to my personal moral ideas of good and evil. If God does or commands something, it is automatically good, since He is good.