Ok well Ill give you some help..
For item "Change Username" only!
Code:
Table Settings (Advanced Users Only!)
Item Table Name - user
Set Type - none
(Those are the only 2 fields with data, everyone else is blank)
Input Field Settings (Advanced Users Only!)
1: Phrase Name - vbplaza_username Field Name - username
(Thats all how it should be, no value either)
Hope that helps.. if it doesnt, you may have to reinstall the plaza.