This add-on was created for customers who want a flexible and an easier way to generate internal recurring invoices. So, the invoice by itself won't be recurring, but the system will send any amount of invoices which you have set up. You can customize the date and how many times the Invoice will go out to your client and not think about it!
The invoice is created manually only once and goes out on the specified by you dates. The customer will be able to pick a payment gateway and use this Invoice to make a payment or as a reminder notification. An e-mail will go out to the user and the admin of the site once the IRB invoice goes out. Unlike recurring payment, the IRB invoice is not for automatic payment withdrawals, this is simply to remind your client of the upcoming payment. There are two options in IRB, one is to send out the Invoices after the first payment and the other is to send Invoices right as you create them. Just like in the recurring billing there is an option to set up dates and Cycles.
No, once an Invoice has been created you may not change the settings, another Invoice would have to be created.
No, the templates of the Invoices do not change.
IRB and WP-Invoice do not store any billing information in itself