You must have posted this to Messenger Plus! General Talk forum, as it has benn expressed there "Here you can talk about anything related to Messenger Plus! that doesn't fit in the other forums." and obviously your suggestions don't fit here
Not programmers, only one programmer, Patchou, and he's trying to read most of the threads, even though he may not have the time to reply to all of them.
As far as I understand, you are suggesting a feature which already exists. We can already create our own emotion sounds from inside Sound Library > New sound...