How to customize an email message on Woo Commerce for Backorders?

Hi,

I own an e-commerce store using woo commerce on wordpress and there are certain products I want to list as allowing for back-orders. I have selected the option for backorders – ‘allow but notify customer’. However I did a test order on an item that was sold out and set to allow backorders, and I didnt receive any notification on this being a backordered item. My questions are:

1. How do i set up an email notifying us when there is a backorder?

2. How do I set up a message/email notification when a customer purchases a backordered item?

3. Does a customer pay upfront when they put through a backorder?

4. Can we set a limit on no. of items allowed for a backorder?

4. If let’s say there is 1 piece in stock, and they select 4 items, does it mean they pay upfront for 4 pieces, 1 piece gets delivered, and the remainder 3 is on backorder and must be fulfilled?

I do hope someone can help me out with this matter! Thank you.