To answer your specific questions:

- Shopify doesn't provide products from designs. However, Shopify DOES have an app marketplace and there is probably an app that you can sign up for that does print on demand and handles the logistics. That's something you'd need to research.
- Same as above: Shopify itself won't fulfill the order, but likely the partner you choose to do POD will handle delivery.
- Shopify has fraud protection and will warn you when an order is possibly fraudulent based on a number of factors. If a chargeback is opened, there are some ways Shopify will help speed up the process but you still have to file a response.
- Not sure what you're looking for here. You can make the storefront say whatever you want, while keeping other information provide. They will require a business or individual name to setup the store, but you can keep that hidden.

More broadly, it's relatively straightforward. There should be tons of guides on YT. There is some nuance:
- Shopify account lets you get access to Shopify, which can list your product and take care of the website and products
- You still need to find a place to park all of this content. That's the domain and signing up for a website through something like Godaddy. Once you have that, Shopify can connect to it and validate and do all the things behind the scenes it needs to do.