1. The link you posted doesn't seem to be working

2. I recently, in another thread, posted this link to a chart which I personally used to install my empeg in my 98 Civic EX. By comparing that chart to the markings on the empeg's wiring, it was actually quite easy.

3. The Mute wire would be used if you had a cell phone car kit or an actual car phone. I believe it's designed so that when the phone rings, the empeg's volume is "hushed" so you can answer the phone without having the music too loud.