1. How do I add more fields on the User_Create User?
2. I would like to fire up a Stored Procedure then "Create user" button is clicked. How? What event? Where do I need to place the code to fire up the SP?

You can check the Create user button click event

There you need to add your code or you can call your SP directly with in create user SP

I am still waiting on how to add more fields to existing create user template or form.

Ypu can edit the template and more fields as per your need

Can you update the status of thread