Visual Studio :: Adding A Reference To A Project?

1. Is there a reason why someone would want to add a reference to an assembly (e.g. System.Drawing) but not add the Using statement? Seems that if you add a reference, you should add the Using statement automatically, but maybe not always?

2. Correct me if I'm wrong, the only benefit of adding a "Using" statement at the top of your file, is to bring into scope an assembly and not have to fully type the class name? So if I have a Using System.Drawing, I can type in
string = Color.Tomato.ToString(); instead of string = System.Drawing.Color.Tomato.ToString();