What can I do with the 46,000 smiley faces I have accumulated?

Hold on to them. You’ll need plenty of smiley coins to acquire new buildings and upgrade existing buildings. The smiley coins and tools don’t come to you at quite the same rate so at the beginning of the game the problem was getting enough smiley coins but as the game is progressing the tools end up being the bottleneck. The tools from the tool boxes seem to in a random order.