I certainly cannot disagree with many of your points highlighting the negative effects of smoking as I was on and off a smoker. But I never had difficulty running up or down stairs I never had stained fingers nor did I ever smoke in my home. But I agree wholeheartedly about the smell even though it never prevented me from mingling with the opposite sex in the numerous countries where I have lived. I have not smoked for 7 months and hope not to ever smoke again but who knows I stopped for 13 years before. I am 70 this month and still run up the stairs without much effort.