All they would need to do to allow this to work is to have an internet connection of any kind connected to the Wii. Whether it be a LAN connection or a wireless one.
Really thinking about it i cannot see how your friend has not figured how to make this work. Go to settings on the wii click internet setting and your off.
it wont matter, only if u get some dodgey chip to chip ur wii then itll matter, the latest chips are probably wiikey2 and D2CKey, and these should allow u to update.
My friend has a wiikey and he can update and do everything a wii can do.