Good piece, Mike - and what struck me most (beyond be the "physicians should what they are talking about" component) was the segmentation of gun owners.
People are complicated with different factors playing into their actions. Accordingly, no single solution would completely solve a particular problem.
The radical right loves to pounce on a proposed solution (cough "background checks" cough) and point out an instance where it wouldn't have helped, thus (in their minds at least) negating the entire proposal.
Think of the homeless problem - when studies show that simply giving money to a carefully vetted segment of that population is more effective AND cheaper, they counter with "they will all use the money for drugs and alcohol". This becomes an excuse to do nothing.
Same thing for gun control. If physicians need to be educated first, let's do that and see how many lives can be saved.
We will never be free of gun deaths in this country - our culture has an unhealthy obsession with guns and using violence to solve personal problems. (oh yeah - and that pesky gun lobby that can funnel almost unlimited funds into the Congress people of their choice) - but we need to get started on something...