They're there for a reason, if you look back at the "history" of the way Boeing cooled the E&E bays on previous aircraft (707/720 and 727) you'll see that it was something that they took very seriously and there was a method of doing it any time the avionics busses were fully powered, in flight or on the ground. If you're running into people who insist on reducing the decibel level tell them they can either install earplugs while on the aircraft, if they refuse remind them to remove the radiators from their cars to save weight and increase fuel efficiency.
As far as the pack is concerned, to my knowledge they're both identical, not sure why anyone would rather run the right pack, though, I prefer the left because it keeps me cool.