Yep, as already said at best DON'T share your internet.
I've done this some time ago, the discos became a constant nuisance.
At least set up a seperate linux network server.
About wireless I know little, only the hints of a developer of german leading wireless network firm

Stay with the good ole Cat5 cable, its cheaper, more reliable, more stable.
If you want to transfer files or surf in the internet, its fine as long as you want to pay the high prices for a good system.
But your mother old hoover, mixer or microwave oven, the drill machine of your neighbour or any other electro mechanic machine will reduce the transfer rate by destroying the packets.
And thats not acceptable for an MMOG.