I some how missed the part about the food aggression. Just think about the thin condition you got Zaicha in.......she might guard food for a while until she understand that there will always be more. So your best thing to do is keep food at several locations around the home. Zaicha can't guard them all at the same time. OR, do as I do and feed portioned meels twice a day comepletely seperate from each other, then pick up ALL food.

Give her time, the "greed" will wear off. Sometimes it takes longer than others, but it will happen.