First, a very nice gallery you have there! Well thought out and well done. As for store ideas, TS2 Open for Business gave us a lot of options that would be nice to have in TS4: toy store, clothing store, food market, game and book shops, arcades, hair-dresser, pet shop - both the pets and their accessories, general store, craft shop, furniture, flowers, probably more that I'm not remembering at the moment. There was even a mini-mall with a variety of established stores and vacant ones where a sim could set up their own. Free Time gave you the option of fixing up cars and selling them.