1. I've had first year breeders lay 12 eggs. It depends more upon the age and health of the female.
2. More so to the overall size. Weight matters too.
3. Depends upon the individual snake. Some lose lots of weight, some not that much.
4. I wash her and the enclosure right after removing the female and placing the eggs in the incubator. This removes the egg scent. I've had them eat as soon as the next day.