you are right. althoug I did have a friend (American) do that.

his English might not be as good as you. In addition, based on your situation, you should write your own not copy others. I just got idea from here how to organize the letter, I mean what should be written, what should not in letter.

其实，我并不认为这样的信会对case的处理有什莫重大影响，只是在无别的选择时的一种无奈的举措，也是为以后起诉移民局积累证据。