1 - Why do you think all those costs would go down? I don't know of a single stance in Brazil where the costs for the government to do was lower than for private sector even when government offer a much worse solution. Just as an example, on something that cost is quite simple to figure out....
A child school in Brazil... you can have one for under 100 USD/month on private school, yet the public equivalent cost the government over 300/month and one of them doesn't have strikes and can still make some profit.
You are only lying to yourself, if you are willing to pay more just because it may happen that in the near future you would cost more than you pay, then someone that isn't costing to the system is paying for you without using, and that isn't moral, even more when it's forced burden upon others.
2 - Go there and develop your nuke if you so much want. Or well when it get sold on your gun store buy it. Or read the above response on why a citizen wouldn't need a nuke to oppress against its own citizen.
1 - A. Economics of scale and examples in countries such as Japan, Australia, Canada, Norway, Germany, United Kingdom, New Zealand that have done so. The United States is a massive market and should be able to negotiate on par with our neighbors Canada. Every day Americans cross the northern border for cheaper medicine.
B. We already have this option for the elderly in the US. It is called "medicare" and people love it. After you get to a certain age the government steps in to help with medical expenses. This is covered by taxing people. For example, when my mom got sick last year here medicare saved her from using a large portion of her retirement savings.
I am not lying, I see precedent in dozens of comparable countries and within my country of how the competing systems work. If the moral argument of taking care of people doesn't convince you, it is simply good economics to not abandon large portions of populace to poverty. This creates a criminal class and massive prisons that tax payers pay for. Social safety nets preserve the middle class which is the best driver of economies by increasing the velocity of money.
I'm a capitalist in 90% of society, it is actual my life in my work. I think there are base aspects that the government should supply collectively through taxation. Examples: Infrastructure, Law Enforcement, Education, Fire Fighting, Healthcare, National Defense, Nature Preservation. These serve the interest of all, and yes some benefit more than others, but it raises the tide for the whole.
2 - Your basis seems to stem from thinking I want the US to be Brasil. Now, I respect and admire aspects of your culture, but I look to Australia or Canada as closer examples want to emulate. They are "sibling nations" in terms of history and culture in how I view policies. Canada is a nice place that didn't decay due to their healthcare or gun laws. It has challenges like any country, but I think they handle these issues in particular better than us.
If you feel Brasil being more like the US system would improve life for people I could understand that as we have different histories, cultures, and economies. I'm not going to tell a Brasilian how their country should be because I don't live in it and understand it the way they do. It is possible for different systems to work better in various parts of the world.