Take a look at the arduino controller app for android. I don't know how the android part works but the arduino side just uses simple HTML to receve and send messages. Since you know programming you will understand this better than I do but in know in use it and love it because it so simple and just works. If you want to use a device other than a wireless device (phone or such) as I assume you do you may want to check out the nrf2401 depending on your range. As for the relays no you shouldn't run relays right off the board it may work but its not good for the chip so use a transistor to drive the relays. The audio shield isn't really that bad to use and when you buy something like this ( not a Chinese knock off ) you usually get some stuff to help you understand how it works.