n=neutral. - is negative + is positive. Drug/Baby are n or - food and shops and each other. Boutiques, Salons, Jewelries + with each other. Bookstores n food, but + Tattoo Shops, Gadgets, Music, and Toys. Supermarkets n to Shops, but + Food. Ice Cream + Toy, Sports, Supermarket, entertainment except hall, and food booths. Restrooms + Cafe, Liquor, Arcade and Cinema, but n or - to others. Other food shops n each other. Gadgets + Entertainment (Hall/Cinema/Arcade) +ATM. Cinema + most food. Arcade + ice cream, candy, atm, gadgets.
Steak + liquor, café, supermarket. Sushi + steak, ice cream, and supermarket.
Customers rather walk to the other end of the floor than use escalator. You can build Elevators on each end, so 2 floors have ceilings, and you can build on second story, skipping the first one, but it will lag the game if you build too much. If you have small space left over before the red border line, you can still put down a small building, therefore increasing your mall size.