I'm reading the third bullet as

But that's literally not what it says. You have to read it as written, not put your own spin on it. And it very clearly and explicitly says a certificate is required to obtain hunting approval, not just to carry a gun. Your interpretation A- isn't what the law says, and B- doesn't even make sense when you view all three together. Why would they include the short-barrelled rifle statute? Does that also only apply to people under 18 who are hunting? Of course not, it applies to all guns in Wisconsin. The certificate rule applies to all hunters in Wisconsin, and the under 16 rule applies to all minors under 16 in Wisconsin.