In Romans 13, the Bible instructs Christians to obey the government because God has placed it in power,
The governments of the world have decided that Slavery is no longer allowed, thus no you are not allowed to sell anyone. However if those laws changed and slavery was once again allowed then yes you would need to follow all the commandments concerning the just way to treat slaves you might own.
Unless the laws or unjust or uncivil.
....Or just simply plain immoral!
Stilla really not answering the questions. I need a definite yes or no to all of them. Government laws really are of no consequence. During the French revolution various nobles were killed under the law, here in the US women were hung under the law for witchcraft. So Yes or no May I sell my daughter, Can I wear clothing of different threads, and can the farmer plant those crops?