^I believe you see the world as an arena where everyone must be free to compete to the best of their ability to advance his own condition as much as possible. And the definitions of "free", "ability", "advance" and "condition" must be initially left to each individual, but eventually determined by the outcome of competition between them. To put it another way, you feel you should be allowed to do anything you want provided everyone else is allowed to do the same equally, with a minimum of common sense rules to prevent total chaos. If others can't succeed in the competition, that is the result of their inadequacy and they have no one to blame but themselves.^

This is a pretty good summary. I do believe in a role for government beyond simple "common sense rules." See this Ayn Rand article.

Note that there is nothing whatsoever in that kind of arrangement preventing anyone from caring for their fellow citizens. Even now, with the government taking over much of this activity (mostly with entitlements), private charity is still over $300 billion a year.

Nobody has a "right" to anything that must be produced or created by another person. That's not what rights are, and not the rights are guaranteed by the Constitution. "Positive rights" are just lipstick on the pig of forced wealth redistribution. But that's another story.

I wish people were half as concerned about the abuses of States as they were about the abuses of corporations. If you look back through history, there are damn few corporate tyrannies. There are one hell of a lot of government ones. It's like worrying about polar bears when you're surrounded by alligators in the Everglades.

"Defending from the abuse of capitalists?" Just in this past century, how many tyrants sold themselves to their citizens by declaring they were going to protect them from the rich bastards and "return" that wealth to The People? How'd that work out? Hitler fogged things up with references to "the Jews," but everyone back then knew he was basically talking about the guys who had the money. Look at the actual propaganda. Subtract the ethnicity, and there's no real difference from the communist sales pitch.

But even granting your premise on government as protector from the plutocrats, how much money do you think it costs the government every year to "prevent corporate abuses?" As an exercise, it might be fun to tally up (approximately) the government functions you listed above and see what it comes to.

The rest of the budget? This.