I don't know about calling in employees for only about 3-4 hours each, it takes forever to do anything and then it's time for them to go back home. Personally, I like the flexibility of opening and closing whenever I feel like. If you have strict open and close hours then it may happen that you don't get to sell anything because no one has made their mind up yet before closing time. It's a good thing that sims prefer to buy the expensive stuff because sales are so few in a working day, so there is at least some reasonable income. My sims are usually exhausted after an open shop day because they usually ring the customers as employees often get sidetracked with chit chat, TV, phone, paparazzi, massages, books, dancing and what not. After shop closes they need to manufacture new cakes, icecream, flowers, whatever they sell, so it's usually one day open, two days closed. It's not much fun running a shop with craftables, I am thinking of maybe setting up some clubs to come craft things for sale, not sure if that would work.