In the first episode of Parks & Rec, Ron Swanson sums himself up quite well in a talking head, when he describes himself as a libertarian.

Libertarianism is a collection of political philosophies and movements that uphold liberty as a core principle. Libertarians seek to maximize political freedom and autonomy, emphasizing freedom of choice, voluntary association, individual judgment, and self-ownership. Libertarians share a skepticism of authority and state power.

His outlook is that the government should have as little regulation as possible, and sees a majority of the things that the government does as a waste of taxpayer money. This feeds into a lot of the lifestyle choices that you have raised, so I'll address them individually:

1. Not visit hospitals and let minor issues become serious

This is the view that people should attempt to first and foremost look after themselves, so he tries to deal with his minor ailments without the help of a doctor in order to be more self-reliant. However, he understands that when an issue does become serious, he needs the expertise of a professional.

2. Believe banks are not trustable and hoard gold

He distrusts other people looking after his own money. There is the possibility of his bank collapsing, and does not trust that they can keep something that he has earned safer than he can. Even if the collapsed bank was bailed out by the government, this would be contrary to his political views of government having less oversight, so does not want to be beholden to that possibility.

It's possible that he could also be trying to minimize how much he is taxed, as he never really discloses how much gold he has or what it is worth, but he does hint that it is a lot.

3. Eat mostly meat

This is likely just because it is something he believes that men do, or maybe he just dislikes vegetables. I think this is probably less a philosophical choice, and more a personal one.

4. Believe in removing government regulation, a bar should be as unregulated as a garage sale

This is libertarianism in a nutshell. Less regulation, less government oversight, more personal freedom.

5. Sabotaging government from the inside

It seems quite hypocritical to seek to make the government smaller, and yet then go and work for the government. But really it is the most effective way for a single person to have an effect on shrinking the state. He is excited to make cuts to his own department, whereas someone who is in favor of a larger state would be reluctant to have less money to spend, so he can help to relieve the burden on the taxpayer better than someone else could.

When Chris Traeger appears in season 3, he says to Ron that his department is smaller than it should be, and he has only 7 people whereas it should have approximately 10. This is why he was such an advocate for keeping Leslie: she does the work of 3 employees, whilst only getting the wage of 1.

6. Not having normal obligations towards friends

This is part of the whole outlook of self-reliance, and voluntary association. He never feels obligated to do things for friends, as he doesn't feel like anyone should have to rely on others too much, and the only things he attends are things he either is forced to, or actually wants to.

7. Not having a mobile phone

Not sure about this one. Possibly an extension of 6: he never feels the need to be available to others as they shouldn't be relying on him, and none of his personal interests require the use of a phone.

I think he is parodying an unpopular philosophy that's familiar to Americans.

It's not so much that he subverts an American philosophy, but rather a modern philosophy.
Since Ron Swanson is an American in America, that of course also has traits of American lifestyles (but does not necessarily mean that it is the basis for his contrarian life philosophy).

1. Ron believes in survival and self sustaining behavior. He doesn't not ask for (medical) help if he can avoid it. Subverts the modern stereotype of people overdoing medicine, e.g. the excessive use of antibiotics for simple ailments. It also helps paint Ron as a man's man.
2. Hoarding gold is an indication that Ron does not trust the fictional value of currency and instead relies on the gold standard (which has been abolished in '71 by Nixon). Ron does not trust the economic sector, but more importantly: he approaches his finances in an outdated way (relying on the gold standard).
3. This also helps paint Ron as a man's man. This is a subversion of the modern stereotype where vegetarianism (and healthy eating in general) is on the rise.
4. Although this can be considered an Americanism, it's also simply a conflict of interest as Ron is a government worker. This is also a subversion of the modern stereotype where the people rely on the government to regulate them (similarly, you often see movies where a utopian future has a government that excessively controls the people by our standards, e.g. the banning of salt in Demolition Man)
5. See 4. This seems to be a self-justification for Ron to accept that he works for the government even though he hates government. This is similar to a vegetarian waiter in a steakhouse, or a recovering alcoholic who is a bartender.
6. Everything I've listed so far consists of Ron doing what he thinks is right, regardless of public opinion. Similarly, Ron will not bend over backwards just so he can have friends. It is consistent with his general character that I'm describing here. This can be considered a subversion of the modern stereotype of an emphasis on social networking (both online and offline).
7. This is a clear subversion of the modern stereotype where everyone has a (smart/cell)phone.

To accurately sum up Ron:

• He's a bit archaic for today's world, and considers modern standards a fad.
• He is a cynic at heart and has little trust in people. However, he doesn't treat people badly; he's simply indifferent to them (as way to cope with his lack of trust in them)
• He very much does things the way he wants to do them.
• He cares little for the social repercussions that his decisions cause.
• Ron thinks very highly of his own opinion and actions. He doesn't think he's superior to people, but he does think his opinions are better than general public opinion.

Most of his "quirky" behaviors are simply a reluctance to modern (relatively young) ideals. He prefers the world a few decades ago compared to the modern world; and his justifications often imply that he sees the modern world as nothing but a fad.

If I had to label him in three words, I'd say that he is a stubborn self-reliant conservative.

Off-topic, but interesting to mention

Ron does what he thinks is right. But it's very interesting to notice that the "weird behavior" you reference is always contrary to public opinion.
But Ron is not a contrarian at heart. He isn't going against the grain for the sake of being contrarian. He does what he does, and is indifferent to whether he goes against the grain or not.

Unintentionally, your question bases itself on a skewed perspective, as you only list things that go against general public opinion.

Imagine Ron held the following idea:

Horses are out to destroy humans. They have only pretended to be an easy and willing mode of transportation so as to infiltrate our society. They are planning a violent takeover. This is why I don't ride a horse to work.

However, your question would have never listed "why does Ron not ride a horse to work?", because no one rides a horse to work anymore. His behavior itself is not weird, because he basically does the same thing that everyone else does (not ride horses). Unless provoked, there would be no need for him to justify his choice of not riding a horse to work.

When addressing the weird behavior of a character, there is an unintentional bias towards things they do differently, as opposed to weird opinions that they hold.
This can change the perception of someone like Ron. Because you only lists the contrary actions, he can wrongly be perceived as a contrarian, instead of a stubborn self-reliant conservative.

The catchall term for Ron's behavior is

rugged individualism.

The stubby Wikipedia entry for that notion focuses on Herbert Hoover, since he popularized the phrase during his 1928 run for office, but the idea is much older and more associated in American culture with the behavior of Theodore Roosevelt, whom Ron is essentially a modern caricature of, by way of Ernest Hemingway's self-conscious 'manliness'.

You could call him a 'parody' of Teddy and the Jacksonian heritage he carried on, since 'parody' can refer to any comic exaggeration. Usually, though, a 'parody' of something is understood as satire and mocking ridicule. The portrait of Ron is much more loving than that: first, since he swiftly became the show's most popular character and the writers couldn't make him too off-putting; second, since he observes all the peculiarities and beliefs of manly Jacksonians but skips lightly over all the condemnation and judgmental hatefulness of many present-day religious Republicans.

Really Ron is, essentially, a fantasy conservative dad created by left-leaning writers: protective, capable, and checking as many right-wing boxes as possible without becoming unkind or judgmental towards members of disadvantaged groups.