This submod of Hospitality adds storefront tab to the cash register, so it can be used to create a small shop. It will need to be staffed, but in return it can give you more silver per sold item. All items in an area around the cash register will be put up for sale.
Hospitality: Storefront Mod features
The customers mood will depend on social skills of your selling force. On top of that the selling price of the item will depend on the difference in negotiation skills of both the customer and your staff. If you put an abrasive mute caveman in charge of your store you will basically give away everything for free and insult your visitors at the same time, so that would not be the brightest move.
What people prefer to buy in your shop is roughly the same as with the hospitality shopping area, if they are hungry they will prefer to buy food etc. But again the social skill will also impact what they buy, with a high social skill you can sell items the customer might not really like all that much. There are always expections of course, you cant sell drugs to a teetotaler or clothes to a nudist, even with 20 skill 🙂
If using both Gastronomy and Storefront and placing a cash register: by default it will be both a restaurant and a shop. Just close the restaurant if you just want it to be a shop. Otherwise your staff might be standing by for the wrong type of job.