I think it scores just once, it is worth 3 if there is kitchen next to it or 1 if not - and thats all. So between 2 kitchens is still 3 points. Otherwise it would be mentioned in rulebook or on the card.
Yup, 100% correct.
Worth 1 point if not beside a kitchen
Worth 3 points if beside a kitchen (regardless of how many kitchens it's beside)