I'm not sure if I understand your plugin right. I use WP 3.5.1 and BP 1.6.5. Installation of your plugin was no problem. I've for BP just the field 'Name', I think this is default. If I change the entry in BP, the change is visible on my profile page too.
After activating your plugin the field changed from 'Name' to 'Nickname'. Any changes in this field is similar like before. I thought if I activate your plugin that only the entry of the nickname will change and the entry of name stays as before. For a better understanding. If a person register he use for name normally firstname and lastname. With your plugin, my thought, name stays as it is and nickname just changes like the user want to display on his profile page. This could be useful if a user does not want to show his real name but the real name is existing in backend.
I'll be thankful for a feedback!