Apparently on my shop, once the user logs in at the checkout process (very first step), the user automatically skips the Billing step and jumps right to the shipping step.
How can I set this up so the logged in user goes through the same process as a guest user?
This is not a default Magento behavior. I would suggest that you disable your custom theme, and follow the Magento standard debugging process.
More information on how to do that here at this link https://www.sonassi.com/blog/knowledge-base/magento-debug-process
Or in this old Magento.SE post: https://magento.stackexchange.com/a/429/336
