1. Don't think, there is straight answer.
2. It probably depends on situation. My aunt for example is probably housewife (whatever the definition may be) but in fact she has irreplaceable role in the family business. They are farmers and there is always a lot of work. And aunt have had also upholstery, but as the farm grows, she don't have enough time for that business. So, I think it's up to each person how they arrange it.
3. It should be definitely choice of woman.
4. This depends on the definition. 😀