I have a couple questions about work hardening 300 series stainless.

Does it get hard enough for something with high strain in a very limited
stretch? Something like a fish hook?

When it reaches full hardness does further working make it start to break
down and get weaker? How much further working?

Can it be carbon treated for additional surface hardness like on the point
of a fish hook?

No I am not planning to get into the fish hook business. Just thinking
about things.