Add more options and types in EVERYTHING- furniture, materials, and building options!!! Also possibly an iPhone version? It'd be so much more convenient for me, especially since I have a 7+, so my phone's screen is pretty big. Most important things (to me at least) are starred.
Furniture- more kitchen cabinets, outdoor furniture, stairs*, fireplaces*, beds, desks, office supplies, shelves*, gym equipment, game room items, kitchen appliances (double ovens, more fridge/cooktop/microwave options)/ accessories (more plates, plate settings, cups, equipment), cars, skylights*, hot tubs*, pools*, craft room supplies, light options (string lights, Chinese lanterns), moulding*, beams*, columns*, built ins*, benches, etc.
Materials- rustic wood*, better patterns that are popular (they're all so traditional and just drab, to be honest)*, tiles (especially tiled and difference in color rather than 1 color throughout)*, stone*, brick (like white and distressed)*, countertops (marble, granite, and quartz variations)*, and metals.
Building options- ability to create a basement and attic, 3D mode that shows the roof and actual ground, vaulted and other special ceiling options*, editing a single room's height instead of an entire floor (i.e. rooms that are as tall as two stories)*, steps up to a porch and patio*, a porch without a railing*, more porch/ patio options*, change direction of materials (i.e. wood planks)