Hello everyone! Finally good news!.
I had my interview today (Miami) and could not wait to share my experience here in the forum. After a couple of mistakes along the way, the nightmare is finally over.
The officer was very kind. The whole interview took 15 minutes. She made us raise our right hand, swear, etc, then asked for our IDs (passports). Then, she went through my wife's file (main applicant as a winner), asked all questions in the application, checked name and DOB. She asked for the original birth certificate and marriage certificate to validate the copies on file. When she finished she started with me, no questions. Just checked my original birth certificate and asked for my employment letter (I am under an H1B). Finally she asked for my son's original birth certificate. Confirmed our last entrance to the US. Did a lot of checks in all the files and ended like this:
"Everything looks approvable, congratulations. You may receive your cards in 30 days"
I just went to the USCIS website, and our cases changed to Card/Document Production!!!!!!
Once again, thanks for all the info and support in this process. It was EXTREMELY useful!
Kind regards