Welcome to PT! Your babies are sure pretty! You will just have to try different foods for them until you find what wroks best for them. All I have ver fed mine is Science Diet. If they are a good weight, kitten food is not needed because you don't want them getting to "fluffy" this young.

No advice on the balcony since mine are completely inside sweethearts and I have a one story dwelling, but you got good advice from the experts here.