How to import Hikashop products, including linking Hikaserial packs?

Hello.
1. How can I import products in Hikashop and include linking to Hikaserial packs in same import file? Can someone show me such csv file example, please?
2. Also can I import Packs to Hikaserial without serials?
"License Pack 1","" is adding empty serial, but just "License Pack 1" is not working, how can I manage it?
3. By default, when I'm importing NEW pack + serial with Hikaserial Import function, I've got Status for refund serials - Free to use. I need it to be Unassigned, but how can set another default status for Status for refund serials? Changing From Free to use manually for each package will take too much time, and there is a possibility that I can miss something and sell refunded and used serial..