> Your problem here is that you're seeing the country separately from the people living in it.
Actually, in this case "the country" refers to the government, not the people living under its thumb. The people can stay; *they* aren't the ones acting aggressively. If the government stops violating others' natural rights, i.e. effectively stops being a government at all, it is welcome to stay as well.
> So the choice becomes you moving or everybody else (who have just as many rights as you) moving.
False dichotomy. No one needs to move. All that is required is that everyone respect their neighbors' natural rights.
> Theft implies you get nothing in return, which is clearly not the case.
False. Theft is when someone deprives you of your property without your permission. It makes no difference whether they leave something in return--something, moreover, which you clearly value less than what was taken, since they resorted to theft rather than a mutually-voluntary exchange.
> That, however, is a particularly American problem. That the US government is fairly broken is well known.
The problems listed are common to all governments, not just the USA. Aggression and corruption are in their nature. Without aggression they wouldn't *be* governments, and the power to get away with "legitimate" aggression invites corruption on a grand scale. Some are certainly less corrupt or intrusive than others, but that isn't much to boast about.
> There are plenty of governments that function better. There are none (AFAIK) that function like you appear to want it too, which indicates to me it's not practical in some way.
It's more than impractical; it would be a contradiction. An organization which respected others' natural rights and did not practice aggression could not reasonably be called a government at all. It is the institution itself which is flawed, not any particular implementation.