5) Unless you don't care what they'll use it for as long as you get paid, in which case you'll sell to anyone who wants one. Free market and all. There are plenty of criminals, so I'm sure you can make a good living catering their needs.
Oh, certainly. Until you get tracked down by people ready and willing to hold you accountable for those actions. Then you're in trouble.
If tracking them down was easy, then the Armory would still be in business.