No Florida law expert (though I am a little familiar with the horrible building codes y'll have - blah) by any stretch of the imagination, but I've had to get around a few Uncle Same laws here recently with one of my "hobbies".
When Uncle Sam puts a restriction on something, say the 3000 laying hen limitation, if you only have 2,999 chickens you do not have to comply at ALL. Of course this doesn't side step Florida's laws, but it'll get you around Uncle Sam.
Additionally, the "free eggs" will work, but it can bite you in the bum. The regulation is for selling eggs, so if you're not selling them you don't have to comply, but they my require you to offer an option with giving them away. Meaning, your "friends which are purchasing the empty cartons" would have to have the option of bring their own cartons, otherwise you're selling eggs again (even though the eggs are free and they're actually purchasing a carton, if there's no other way to get them you're selling eggs and cartons).
I'm sure there's a way around the law if you put "free", or "animal feed", etc. on the sign, etc. then simply tell the "friends" the actual story of why they're labeled that way.
Good luck!