Wrt point 3) I don't think it is unreasonable to assume that the default interface chosen in the installer will also be the default interface in the installed system. So probably the installer should write persistent-net.rules, not udev at the first boot.
Wrt point 3) I don't think it is unreasonable to assume that the default interface chosen in the installer will also be the default interface in the installed system. So probably the installer should write persistent- net.rules, not udev at the first boot.