Just got back from my weekend at VA Beach with a group of DB's. Had a wonderful time.
The only thing I saw that you could change is: "2. Cheerfulness. In other words if you agree to do something do it cheerfully or not at all." Maybe you could say, "......or tell me you do not want to do xyz."
My 2 cents. Tell me how it goes. I think the letter idea is great. nik