The term "Blarg Elite Guard" is conjectural. The real name is unknown, and a non-canonical nickname or title is used instead. See the reasons for this title in the "Behind the scenes" section below and/or the relevant discussion on the talk page, if they exist.
Their main weapon is a blaster, which fires deadly orange-yellow blasts, capable of large amounts of damage. Elite Guards, though never fought in space, can presumably breath in space due to their gear.