Comparing population density is overly simplistic. You've got to compare vehicle density, intersection density, sidewalk to road areas, average commute distances, traffic control models, climate, and a plethora of other statistics. For example, if Barcelona only has three cars, of course there's going to be less traffic fatalities.
Wait a minute! Let's not forget the first A in NASA. They do some serious aeronautics research that Musk likely would not be interested in doing. I'd hate to see vital research be dropped because all the money went to SpaceX instead.
The only point I see behind going to the Moon is to test on orbit docking, thrust, in transit spin artificial gravity, and the like - a quick Apollo 8 style loop around as a shake-down rehearsal for trans-Mars procedures.