The "man with the gun" was present when I was in the CDG lounge too. He fingered the magazines a few times and generally looked ill at ease. I supposed he was just part of the increased state of alert that France is under at the moment but his presence did seem incongruous with the ambience of the lounge - and that feeling was written all over his face throughout.
Oh - and excellent report. Pretty much summed up my experiences, at least those we had in common.