US Immigration from Zimbabwe

I filed my change of status and l realised l put a wrong document how do I delete and put a new one

I'm filling out my affidavit of support and I'm on page 4 where it wants me to calculate my household size.

It says:

- Enter the number of persons you are sponsoring (just sponsoring my wife, so that's 1)

- Yourself (that's 1)

- If you are married enter 1 for your spouse (that's 1)

Then it adds up to 3, but really it's only 2 people.

Which one do I leave empty, so I have the correct number of people?

I believe I read that the visa is supposed to expire 6 months after the medical exam, but my fiancee just got her visa in hand and the expiration date is in December despite her medical exam being in February (so I thought it would've expired in August). Does she really have until December or should she be making plans to leave ASAP?

My fiancee's visa was just issued, but she no longer lives at the house where we set up home delivery. It doesn't seem like there's anyway to change the delivery address. What do we do?

Is it possible to transfer the case to a different embassy even after the interview?