-- If you're not sure what I mean by passing qualifications those would be no felonies, no domestic violence, no habitual drug use / convictions, & no history of mental illness. --
Precluding ex-felons from owning guns to protect themselves is in itself a form of gun control. There have been people railroaded by overzealous prosecutors in the past and will continue in the future (Martha Stewart comes to mind). Many felons not only paid their debt to society but also have become productive members of society. This prohibition imposed on them would simply drive them towards the black market for guns.
Also, why would habitual drug use strip a person from his or her rights? As long as they do not commit crimes, I don't see it.