I'm going to make this even simpler... In the future, if slavery were ever again legalized, would it be considered 'sin'?
The answer is NO. Sin is considered going against divine law. In this case, Yahweh's law. No such verse says not to own others as property with beatings.
You are taking a page from necessary regulations and legal structure for a rather barbaric culture, an you are attempting to imply that it's a universal permission and justification to have such culture as an ideal.
I'll make it simpler for you :
I'm a vegetarian, and I cling to a certain ideal in respect to my diet and treatment of animals. We could say that on a personal level (for me) I view certain animal treatment and food farming as barbaric and immoral. Let's say I convince the current president of that, which is not going to happen, but let's say that I did.
So, the president will get up on the podium tomorrow and will say "Guys, eating meat is a part of the barbaric remnant of our past, we should have better respect for life... so eating meat is illegal from this day on". And he signs an executive order making killing animals for food illegal.
What do you think would happen realistically? Would people stop eating meat? Would people stop killing animals for food? Would people start enforcing such practice?
NO. Absolutely nothing would happen. The conservatives would bury such president alive, and liberals would dance on his grave.
So, the best he could do is donate some government charities to education on this issue, or become a vegetarian himself, or create some general regulations against cruel treatment of animals, and lay out some principles that would eventually result in a paradigm shift in our cultural understanding.
So, in a scope of moral proclamations, the plausibility will only make sense with established cultural paradigms.
Eradicating slavery doesn't result by making a specific moral proclamations, but by shifting cultural paradigms in which such moral proclamations would make sense.
Hence, your understanding of this issue seems to stem solely on basis of proclamation, as though that's what drives our motivations, and that's not the case. A single statement of "This is wrong" or "This is Ok now" will not result in a cultural paradigm shift.
It's very very simple... If slavery were ever re-legalized, for any reason, it is not sin, according to an instructed book inspired by Yahweh.
Again, coming back to this issue. I'll make it very simple for you too
We could make a list of rules for your kids:
1) Don't hit one another.
2) Don't spit at each other.
3) Don't pee on each other.
4) Don't yell at each other.
And then they come back and ask... is throwing rocks at each other ok? So, you ad it to the list and say. No, it's not ok. And then they come back and say, "Is it ok to throw a piece of wood then?", and you add that to the list and say "Don't throw hard objects at each other".
And the it goes on and on, until you basically say: "Don't do something to each other what you wouldn't want other person do to you". Or, "Love one another, and here's what a loving attitude is like... it's patient, it's kind, it's forgiving, etc".
So, concept is that principled approach to morality will transcend context.
What you are doing is very much like the kid in the above illustration... saying "But there's nothing here that says that owning and beating people is wrong. In fact, here it says that it's ok".
And then I keep showing you a transcendent principle of :
"Love one another, and here's what a loving attitude is like... it's patient, it's kind, it's forgiving, etc".
"Don't do something to each other what you wouldn't want other person do to you"
And what you seem to imply that such principles don't encapsulate such behavior as wrong and immoral. Why would you think so?
You seem to think just because someone could point to this verse, then it will automatically justify slavery, but it's absurd when it comes to a wide variety of
transcendent principles that would clearly condemn and invalidate such behavior as wrong.