1. Chlorine will gas off with time, but you should use a dechlorinator to avoid shocking the fish. These contain sodium thiosulfate and are relatively inexpensive. Incredibly inexpensive if you mix your own.
2. Your water will settle after 24 hours of aeration.
3. You definitely need to warm up your water in the winter and cool it in the summer. The simplest way in the Summer to cool it is to mix with cold tap. Aeration is far less important in the summer.