In the module located at app/code/MyCompany/MyModule there is a JS module in the file view/frontend/web/register.js. The Magento base URL is https://magento.host/ and the luma theme with the en_US locate is used.
What is the public URL for this file?

You are developing a new theme which inherits from the Magento_Luma theme.
How is this accomplished?

You are adding a child node to the product.info block using the XML:

How will this block be rendered?

In a code review of a merchant's site you have discovered that there are multiple observers for the checkout_submit_all_after event. After closer inspection, you notice one of these observers is relying on the others being executed before it is called.
What risk does this pose, and how can it be mitigated?

What is the connection between product attribute sets and categories?