Dancing and air guitar are often celebratory gestures. So PHB is saying that the way to deal with no longer having a soul is to celebrate. I guess it makes life easier for a PHBs to not have a soul when they make the decisions that they do.
I think the air guitar reference just means that it's an empty, meaningless, over-used gesture that people do when they can't think of anything original. I don't get the dance thing, though.
Actually, I don't understand the reference either.. Just think, Plasma: Had you kept your useless comments to yourself on the other strips, you might have had an answer here. Provided you even read what's posted, but now it's been many months. Le sigh.