Every ranking I've looked at has the US at #1 in the world in GDP usually with more than twice the number two (China). The only studies I've seen that rank the US at #2 are ones that lump the entire EU into one category.
As far as life expectancy you are right that the US falls about 4 years behind depending on what numbers you look at. How much of this is lack of healthcare and how much of this is the horrible, horrible diets most of us eat?
The lack of healthcare insurance causes a lack of healthcare insurance? Not sure what the point is.
What is the actual cost of people not having preventative care? What is the impact?
Less worry and stress? I call BS on that. People here are worried and stressed no matter what their healthcare situation is.
Competitiveness in what way? In what areas areas are we not competitive?
Quality of life? The US ranks #4 in the HDI according to the UN in 2011.