In the past BATFE inspections were arranged in advance, but in at least one area recently several dealers were "hit" at the same time with surprise inspections. Apparently, the idea was to keep one dealer from warning others. They did a nit-pick job, citing 4473's with the height or weight missing or illegible, etc. Few dealers escaped with no violations.
As far as dealing from home, Clinton's administration set out to eliminate home dealers and did a pretty good job of it. The justification was that many home dealers were not really dealers, but guys getting cheap guns for their hunting buddies. I would like to be able to say that was untrue, but I can't because I knew several "dealers" just like that, and some of them didn't bother to keep good records either.
I always advise anyone who is serious about going into the firearms business to set up a properly zoned shop, get all the local and state licenses as well as an FFL, and play the game right. If you keep proper records and keep your nose clean, you won't have any problem with the feds.
One main reason to keep your business and home separate is that your home won't become a target for burglars looking for guns. Also, you won't be rousted out of the sack at 2AM on opening day of deer season by some idiot who put off buying his gun or ammo until the last minute.
Jim