2/? I know that hornmothers are known to smoke pipes from time to time, but I have done my utmost to prevent that. That way they will have a lesser chance of laying more defective or dead eggs. Seeing @muscle_Horn smoking was a shock to me.
Haremhorns in the witch caves allow it since it seems to calm the hornmothers during stressful situations. Perhaps under those conditions the tradeoffs are worth it (and in any case haremhorns don't know about the negative effects of smoking).