The list seems to be exhaustive now. However, I would just add that you should hold an "Open House" every month where employees are free to share their feedback and suggestions, to which you need to respond.
In addition to this, you can read a very good and easy book called "Fish! A Remarkable Way to Boost Morale and Improve Results" by Stephen C. Lundin, Harry Paul, and John Christensen. Many companies worldwide are implementing what is now known as the "Fish Philosophy." We even held a workshop based on it, and it does work.