I would just add a wiggle expression to the camera or background….ALT click position of the camera and type in wiggle(3,15) thats 3 times a second it moves 15 pixels..you can change your numbers til it matches close…
Also this expression might help out. if your characters are 3d then you can alt click the Y rotation and paste in
delta = toWorld(anchorPoint) – thisComp.activeCamera.toWorld([0,0,0]);
radiansToDegrees(Math.atan2(delta[0],delta[2]))
this will make it so the people are always facing the camera