Ruling on the fasting of one who only prays in Ramadaan

Does he have to refrain from eating on the day he becomes Muslim?

Is it permissible for the owner of a restaurant to sell food to those who are not fasting and to kuffaar during the day in Ramadaan?

Employing non-Muslim workers and allowing them to eat in front of Muslims at the time of fasting

The fasting person may eat if he is not sure whether dawn has come but he may not eat if he is not sure whether the sun has set

Taking lots of baths when fasting

How should people fast whose day is very long and the sun never sets for them?

Ruling on sitting near equipment that emits steam or smoke whilst fasting

He travelled during Ramadaan to a country where the people started Ramadaan on a different day