1) If you are a legal resident of Indiana, do not even TRY to sell your gun outside of Indiana.
2) Ask the buyer to see their Drivers License to verify they are also a resident of Indiana. If you sell to an out of state buyer, you risk being arrested on the spot.
3) It sure doesn't hurt to ask if there is any reason the buyer can't legally own a gun. You never know what you will hear. Asking if they have been convicted of a felony is too narrow.
I expect to see more sting operations at gun shows, whether initiated by bloomy or not.
Well a couple of things you said were pretty obscure, like selling a gun outside of Indiana, if you can quote federal code, or Indiana Code, I would love to see where I cant sell a gun outside of indiana. The law states that I cant sell a HANDGUN to someone outside Indiana, without it being trasferred via a FFL, but since the law does not require me to gather any information, that is pretty much a moot point also. As for asking for a drivers license, again since there is no federal or state law requiring the gathering of ANY information on the purchaser other than a cursory attempt to verify the are not considered a "excluded person" I am not saying that a person should just up and sell a firearm to someone with no questions asked, but the law doesnt require any questions to be asked.
INGunGuy