I think it would be beneficial to be able to collect additional information (add required fields) through the form when a new user creates an account.  In a sense, it would combine an inquiry form with the user creation form.  We don't want to require users to submit an inquiry - we want them to be able to create an account for themselves.  However, with this, we lose the opportunity to gather critical data (like referral source) if they never take any action after creating an account.