As for your first point about indoor air - Gas for heating doesn't mean gas cooktop and non-gas for heating doesn't mean non-gas cooktop. I have oil heat and a

As for your first point about indoor air - Gas for heating doesn't mean gas cooktop and non-gas for heating doesn't mean non-gas cooktop. I have oil heat and a gas cooktop. The gas is propane which is supplied by a company who fills a tank once in a blue moon. My parents have gas heat and a fully electric cooktop. FWIW, One of my burners is definitely unsafe, the fire is too high and there's a distinct smell of gas after using it for a couple minutes. So I don't use that one...