We really don't see a purpose in assigning Inquiries usernames as many won't ever apply and this will create less confusion for our constituents who do go on to apply as they can then click the First time logging in button and it actually be their first time rather than have a User Name set in the back-end that the parents may not know about or remember that they have.
I would take this option or have since the only UN that can be used is the email address, when marking "create new user" during the processing of an inquiry, the field should auto populate to create a username vs having to generate those seperatly. Also the ability to put the username in the reply email for inquiries