This sounds like a terrible idea. The point of having names is so that we know who people are. If we can change our names all the time it'll be just like an anonymous message board, which would make me sad (and you wouldn't like me when I'm sad).
You should probably make them wait till they have a certain post count (like 50 or something) just to make sure they don't use it too early and have to ask for a new one.
You should probably make them wait till they have a certain post count (like 50 or something) just to make sure they don't use it too early and have to ask for a new one.