Will items from my Wanted List be automatically deleted after I order them?

Items from your Wanted List will not be automatically removed after purchase. You can, however, view the items you have ordered and modify or delete them. Here's how it's done:
First, you have to customize your My Orders Placed page to include "Items in this order on my Wanted List". 
When you enable this option, you will now be able to see a Wanted List icon (it looks like a scroll) next to your orders placed:
Clicking the Wanted List icon will take you to a new page where you can edit/delete or move these items to a new Wanted List.