OK, I've one suggestion for this thread, while requesting new username it should be in this form:
So we can see old username also.
Only this form should be accepted.
When the admins are changing their name of the users, they quote the post requesting it, you see the old usernames in the quote. Your form would be more convenient though.
What I want to suggest to the mods is that you know when a user(whether his is premium member or not) changes his name, his former usernames should in the user's profile. There is another forum who does it and think this forum should do it as well because once a user changes his username we may not be able to recognize who the user is. If we see the profile and see his former usernames, it would be of great help.