Kim,
While I wont pretend to represent GUE in any way other than as a life long student of diving, I may be able to offer you some insight into your frustration. You acknowledge that smoking is unhealthy, and it does limit respiratory function. Because one of the main philosophies of DIR diving is team unity, if one member has physical limitations (or risk factors) the whole team assumes those risks. Much like your light is a "team resource" so are your lungs, brain, and awareness. GUE does address caffeine and alcohol, in fact if you ever manage to take one of their classes, you'll find out that you'll sign an agreement not to drink during any diving activities. I know when someone tells you that your "hgabits" somehow preclude you from an activity you love, it's natural to become defensive and insulted. Put that aside and use it to motivate you to safe your own life by quitting smoking. Until then, dive safe and dive often.