All the different things you can sell is great; but the fact that they’re all counted as different business types is not.
All retail businesses are essentially the same; save for what is sold and how the customer gets it. Self serve (grab a basket and fill it), counter service (the cashier serves you), and table service (you order, and pay the bill at the end); this would be determined by the counter type. Self serve requires a basket or trolley, counter serve is for fast food and beverages, table serve obviously requires tables and wait staff.
You should then fit out your shops to sell the goods in the way that you want them; some things would work for multiple service types (coffee shops for example might be counter or table service or even both, or with a vending machine you could make them self serve).
This would then open up the ability to create unique stores that take advantage of bonuses (and penalties) from mixed goods. For example.
Bookshops - adding coffee entices customers to stay longer, but may spend more (if they’re more affluent, so a higher class, lower traffic premises would work best). It also increases the rate at which the store gets dirty so it requires more cleaning. Adding cake increases the effect. For the effect to work, there need to be tables and chairs. Adding comfy chairs to a bookshop would result in a chance of additional sales if people use them. This all takes away floor space, and a bookshop would benefit from having more bookshelves implying a larger selection.
Gift Shops - adding bottled water, soda or ice cream attracts customers (when it’s warm) and may result in more gift sales. If your pricing is wrong then people may come for the drinks/sweets and not the gifts. More gift shelves (implying larger selection) would increase sales, but certain clothes (T shirts and hats) may go well depending on what types of customer you attract; as may things like flowers and luxury chocolates. Tourist area = cheap gifts, residential area = flowers and chocolates.
Fast Food: adding salad and condiments is complimentary to burgers and hotdogs, but increases requirement for cleaning. Adding further selection may slow down service and obviously create stock buying/storage problems.
There will no doubt be a lot more cases where you could tailor your retail business by mixing goods, furniture/fittings and service types - what can you think of? What would be the benefit and drawback of each?