Hey sorry I realize after reading all the other posts that I rambled in a tired stooper and needed to be more clear.. Therefore I started over and posted a whole new clear and concise thread located here...
To answer your question the relay is always powered via the 5v pin on the particle. As far as I know there is no way to not power this? However, I cant imagine that is alot of power while the relay is off.
Secondly the raspberry pi is hosting a media server in the form of squeezebox as well as airplay. I have a hifiberry amp+ dac board on the raspberry pi that powers some speakers. The amp and pi use alot of power even at idle compared to a particle so that is why the particle is incorporated to switch a relay that turns on and off the raspberry pi and amp combo.