Lyric discussion by drc 

Cover art for Rotating Head lyrics by English Beat, The

To me, "Rotating Heads" seems to refer to people who must constantly look around them for signs of danger ("Coiled up and tense, remains on the lookout.") A mind like a "gin trap" (we would say "like a steel trap" in the U.S.) describes someone who is quick-witted. The imagery seems to invoke a Secret Service agent or bodyguard:

"keeps on the right side" (could mean literally the right hand of the person being guarded, or the morally correct side, or both) "Expects to be shot or get given the bullet" "friends in high places" "Each new passer-by, a new wave of suspicion" "In less than an hour, the plane will be leaving" "The lights and the cameras"

The line about the briefcase might be referring to the "nuclear football", a briefcase containing the nuclear launch codes that accompanies the U.S. President everywhere he goes.

Swollen ankles are a side effect of frequent airplane travel.

My Interpretation