Personally, I don't see what the big deal about the background check is. It takes 5 minutes, all the while I'm happily fondling my new piece. I do however, see an inconvinience in mistaken identities and things like your driver's liscence being 2 days out of date (happened to my dad).
Anyway, I think MG's should be in league with everything else. Handgun ownership age should be lowered to 18 (The Marines can issue me a pistol to kill with, but I can't have one for target practice in the "free" U.S.A.? Same thing with full-autos) SBR's should not exist (Hmm, let's see. I can buy an AR-15 pistol....but I can't put a light stock on a ruger 22/45?).
New manufacture MG's should definitely be legal, that's just common sense. Hmm... maybe no criminals will ever get full-auto guns if we stop production of new ones....yeah, that idea has had almost 40 years to work and has it? Nope, just ask anyone who was in the north hollywood area a few years ago.
silencers should be alright too, hell even encouraged because of noise reduction (could end the whole: "Some people moved in and started complaining about my shooting and now I can't shoot anymore" situation) Besides, it's not like some G-unit thug can go around killing anyone unnoticed because he's got a can on the end of his gun. The only people that have the skills to do that have better things to do with their time.
Just my thoughts