Hello Naber,
Thank you for submitting the questions here:
1. Regarding shipping, normally if you sell downloadable products, then there is no shipping required. The downloadable files will be sent to the notification email after customer place order.
2. Currently, there is no additional field for category like that. However if you want, I can make the customization to make it work as your expect.
If you have any other questions, don't hesitate to let me know.
Sincerely, Giang