Exactly. Zoning laws tend to have something to the effect that limits:
1) parking
2) noise
3) dust
4) efluent
5) signage
7) number of visitors per day.
One thing the ATF investigator told me was that the internet and places like Gunbroker.com have fundamentally changed the way they evaluate applications for FFLs.
She (yes a female investigator) told me that she had someone who she worked with who did 60 (!!!) guns a month on gunbroker and would not do a face to face transaction even if you lived next door.
All of a sudden business hours become meaningless. In fact the only reason you put business hours on your app now is so that the agents can do an unannounced compliance audit during those hours.
I looked at the regs around the business hours and came to the conclusion that you cold probably put 1:00am to 2:00 am as your hours and there is nothing they could do, but for me it wasn't worth pushing it.
I've read of some FFLs doing this to minimize the chance of an unannounced compliance audit, but to me its pointless. I found the ATF to be the easiest to work with of all the government entities I had to deal with while getting my FFL.
The most difficult was my local zoning.
To that end, I suggest that anyone who is interested purchase this book:
http://www.amazon.com/The-Complete-Guide-Zoning-Environmental/dp/0071443797
I purchased it several years ago when a home in our neighborhood was purchased by a New Yorker who wanted to knock it down and build a home that was completely out of scale for the neighborhood.
The knowledge I got reading it served me very well when applying for a zoning permit for my home based FFL.
The other thing I'd recommend is a subscription to FFL123.com
You don't need this subscription, but it puts all the info you need in one place and provides plenty of completed applications.
Don