There’s no need to “make it legal”, things are legal by default until a law is passed to make them illegal.
Yes, and that’s already happened: it’s called “copyright law.” You can’t mix things with incompatible licenses into a derivative work and pretend it’s okay.
Yes, and that’s already happened: it’s called “copyright law.” You can’t mix things with incompatible licenses into a derivative work and pretend it’s okay.