Are you a lawywer, semantic? If you know the Constitutional Law and heard the entire oral arguments, I’d feel a lot more at ease.
I think that the approach you outline is very rational. The issue is, are you able to determine from the Q & A the outcome you propose? No offense intended; just for my clarification...
Everyone should do themselves a favor by devoting 90 minutes to listening to the podcast. In the alternative (or in conjunction with), try Google News; there's around 4k reports, each with a similar narrative.
You will soon see why liberal MSM types intuitively sense that even the most liberal members of the court simply cannot get past the 2A's plain meaning. Even more importantly, the entire Q&A was in the context of contemporaneous construction.
IOW, they were focused on what the founders meant, and regulations of that era (eg Stevens' gun powder analogy), rather than on 150 yrs of precedent. In fact, Kennedy repeatedly mentioned that Miller was insufficient...
They're gonna rule that the 2A is an individual right beyond soldiering (ie no militia requirement). They will leave open the question of reasonable restrictions/regulations to be fought one by one, jurisdiction by jurisdiction.
Roberts will go for the strongest unanimous decision he can get and rely on future generations to restore their full rights.