Automatic namespaces import
Yes, Visual Studio can add the using
for you. When you type in a class name, hit Ctrl + . and then Enter (the first option is 99.99% the right one, so just hit Enter). And you can have it add the using
at the top of the file for the namespace of that class. I use it all the time.
This is easier than Shift + Alt + F10 + Enter as it's fewer keys and the . and Enter are closer.
When the red caret appears at the end of your member, just hit Shift + Alt + F10, then use arrows keys to choose the right option:
Look at JetBrain's excellent ReSharper product. It does this for you.