Understanding User Management and Counts in my Zoho Creator Account

Understanding User Management and Counts in my Zoho Creator Account

1. Are external users with access only through the customer portal counted and billed for the same as shared users ?

2. I have 36 active users in my User Setup Page whose usernames do not always match that listed in the application's shared list despite having the same email addresses. Why? 

3. Customer Portal users show up in the application shared list but not in the Zoho Account User Setup Page. Why?


Zoho Account User Setup Page:
  "johnsmith" (App shared list below shows same username with additional 1, why?)
  "janedoe2"  (Where is janedoe1 and why is a 2 added in the account setup list?)
  "bobbydoe" (Why is the username here the same as in shared list, i.e., why was a 1 not added in this case?)

Application Shared List:
  "johnsmith1"
  "janedoe21"
  "bobbydoe"
  "jamie.doe" (Why would this username not show listed in the zoho account setup page?)

Thank you
Ricardo