In general- they will want to be sure that you DO intend to "engage in the business" of buying and selling guns for a livelihood- and not for your personal use. And that you have covered local legalities- zoning, licensing, etc. Then they talk to you.
You are about to get a good, in depth lesson in the legalities of being a FFL. My honest suggestion- have a pot of coffee for the two of you, have a couple of legal pads and a couple of those pens with a LOT of ink- and start taking notes. The lesson is free, and stuff you are going to need to know to stay on the good side of the ATF.
What we have here is... failure- to communicate.