300 Million guns–a response

Hello all.
I received the following response to my 300 million guns post from Brian Dewhirst.
If gun ownership is correlated with gun violence, and we own ~300M guns, why are there so few gun fatalities? (We own on the order of the same number of cars, and cars are associated with far more fatalities. Vastly more accidental fatalities as compared to accidental gun fatalities.)
What proportion of gun fatalities are older Americans ending their own lives due to debt and/or health situations? (Of the approximately 30,000 annual gun fatalities, what proportion are suicides?)
What proportion of gun fatalities are due to drug prohibition? Of that proportion, how many do you believe would be stopped if the firearms in question were illegal? How many of those firearms used in drug-related shootings were obtained illegally?
What is the psychological profile of a mass-shooting shooter? What measures do psychologists recommend to minimize the frequency of such incidents on account of that profile? Would banning some/all guns/weapons increase or decrease the attractiveness of firearms to such an individual? How likely is it that a ‘ban on all guns’ would result in an Oklahoma-City-style bombing, or bombings, or other acts of terrorism by self-styled ‘patriotic’ domestic terrorists?
Assuming mature 3D printing technology becomes available, how would a total ban on guns be enforced? Which is more important, banning/heavily regulating mature 3D printers, or the improvements in the material existence of ordinary people that said printers might bring (as compared to the numbers of lives which would be saved by said bans/restrictions)?
In what other circumstances do you advocate prohibition? When/where do you believe prohibition has been successful when significant demand for an item exists?
In your opinion, how skilled are police officers with firearms? Are you advocating banning police from owning firearms? How might the behavior of American police officers change were firearms illegal (for civilians)?
What other rights, apart to the right to own firearms, does the second amendment protect? What other consequences might there be to a repeal on the 2nd amendment?