Do you think we should respect a moral system that accepts slavery as much as one that doesn't? If not, then you're not a moral relativist, and that's a relativist fallacy.

No, they're not equal. They're relative. They're a product of the context and environment.

I have a superior moral system than the one I had as a child. Not because my values have changed much, but because experience has helped me to understand others and I've been able to examine and refine my moral system through that

But they're all based on values, which are not universal. I value minimisation of suffering, freedom, and quality of experience of life.

If I lived in a time where slavery was common, and I had the means, I think I'd probably have a few slaves.

Because the right to freedom doesn't exist in that situation. I could minimize suffering and increase freedom by buying slaves and giving them autonomy - ideally I'd get informed consent beforehand too, but I'd give them agency in the course of their life in return for service. I'd use that service increase the number of slaves to maximize freedom for as many as I feel able to do so, in whatever form that takes

Rights are absolutely alienatible. I think everyone should have the right to food, shelter, and maximization of freedom

But we don't have that. These right are alienated, people starve while food is wasted, people are homeless with empty houses everywhere.

Women only have the right to vote so long as they have the right to vote. Chatel slavery still exists, as punishment for a crime. Rights don't exist if they don't exist in practice - anything else is just a rhetorical device

You talk of rejecting contradictions, but there's no ethical consumption under capitalism. Do you live on the streets and sustain yourself on trash? Is that an ethical obligation?

There's no contractions in maximizing good things and minimizing bad things - we all live in a very fucked up world