I have read and re-read the documents checklist and it is ambiguous and confusing:
Actually the checklist is quite clear. My husband is also Cuban and the requirements for applications out of Cuba have specific requirements and it's crucial you follow them. As ariell mentioned there are a few forms for which you need to send in along with 2 additional copies and for all Cuban nationals you MUST send all original documents along with a certified translation. If you send copies your application will be returned.
When my husband got his Visa they handed him back all the original documents that were included in our applications, as well as all of our pictures and additional information (phone bills, trip itineraries, letters, etc). Our CAIPS notes indicated that they made copies for the file.