How long does it take to get back my passport from VAC NYC?

[JourneyPL]

I received a letter asking me and my son to mail passports to VAC in New York City (family sponsorship category). How long does it take for them to mail my passport back? I have an important international business trip around the 22nd of next month.

The second question: do I have to fill Appendix A if nothing has changed since the application?

Thanks.