Grayson Islands

Well, they have legalized slavery, and mages are a privileged class, so I assumed there might be other irrational things as well.

I understand, but they have something like slavery contracts. A child cannot sign such a contract. If you have questions about such details, feel free to ask. Because I can't go into detail about every aspect of life and legislation. And even if I could, it would turn into a Wikipedia article.

What about a less powerful sword? And how will the accuracy of the throw be determined in this case?

Thirty. It will be determined by perception.