You are not being unreasonable. I insisted that everyone wash their hands regardless when touching my newborns - it was only once they started moving about and crawling and picking up goodness knows what off the floor that I let that rule lift.

No one smokes in my home. I don't care who you are it is not allowed - no, not even in the backyard. If you can't visit me for a few hours without lighting up then don't bother coming over. My children's (and my) health is far more important to me than your habit.