Comparing the US to small nations with a fraction of the population is kind of silly.  The magnitude of issues is nowhere near the same order.  Even comparing different parts of the US to each other isn't a simple task.

Right, like the Republicans have been able to fix anything.  lololo

Both parties have had their chances and both need to be held responsible.  I can't even imagine the viewpoint that would give either a party a passing grade.

simple answer: no

longer answer: we were, but little over a year ago, during a reevaluation of the country, we were demoted from a developed country to a developing country due to our astronomically high poverty rates.

The U.S is definitely developed but it obviously has a few issues. Well, every developed country has issues. Like someone else has mentioned, I suggest you check the Human Development Index which takes in a variety of factors like some that you have mentioned. The U.S is currently sitting at No.10 tied with Canada.

I'm almost tempted to think this is clickbait.

A number of these statistics are incredibly misleading or lacking in context, but even if we were to consider them as is, the US still outperforms 75% of the world in nearly all of them except for income inequality (and it's worth noting that US citizens are still some of the richest in the world regardless of how unequal they may be). There are certainly areas where the US lags behind the world leaders in development, but to call it undeveloped as a whole is just silly.

We are a nation full of idiots and crazy people. The founding fathers were outcasts from Europe. Basically, I just wanted to say this... Fuck puritans

To be as blunt as possible, yes, income inequality is real here and it is a bit extreme in some cases where you have a CEO getting paid 50-300x the amount of a regular (I think that is insane btw).  But if you really want to know what exacerbates that chart, it is that America, on top of having extreme income equality, has states that are much poorer than others.  So if you take the poverty of some place like Mississippi's highest and lowest paid and compare it to some place like California, its going to look more dire than it really is. 

I won't say that the US is not developed.
But it sure has a lot of big problems, the 3 main ones to solve being free Healthcare, education and gun control. This is how you reduce inequalities, give everybody a decent chance.
Now we know the reality is still different, even in countries with free education, you can't become anything you want to be. But at least you'll have a chance of having a good or great job.

GINI is not a reliable marker, however. It looks at inequality and disparity in wealth between the poorest and wealthiest. While it indicates the extent of inequality, it does not factor in other important qualitative characteristics, such as the the cost of average living (which, if low, even the poorest can get by), nor does it highlight how the poor of the country in question fare vis-a-vis other countries. USA has huge economic inequalities, but the average living conditions even for the poor, are still much better than in other less developed countries.

First on inequality. Do you realize that the United States is pretty much a continent? We've got 50 states plus a federal district and some territories. Having equality on that kind of level is impossible. Chances are, if you're living on the east coast or the west coast, you're going to make more money. Like in most of the world, coastal regions are far more prosperous than land-locked regions. Mississippi could never compete with New York. There's nothing in Mississippi that could make that happen. However, there is a catch to all that. Living in the city is very expensive whereas the cost of living a rural southern region is much cheaper meaning that you could get a lot more for less. So why should it matter if someone from Mississippi makes far less than someone New York if the person from Mississippi can buy a bigger house than the person in New York for far less money?

As for the crime rate, a lot of that comes with population. The US has a population of 325 million people. Japan has a population of 126 million. Canada has a population of 37 million. Then you get to the European countries, their population figures are also in the tens of millions. So it would make more sense for the US to have more crime. However, crime in the US is currently the lowest it has been in decades. There are pockets of areas with high crime rates, but that can be blamed mostly on incompetent politicians in local governments.

Then there's healthcare. The funny thing about that is health was very affordable until the government became more involved. Aside from the healthcare problems, if you walk into an American hospital, they're some of the best. They may be as expensive as hell, but there some of the best. They are certainly far better than that hospital my friend had to go to when she was in Rome. The fact that the hospital had wooden floorboards terrified her amongst many other things.

As for the government, the US isn't really any better or worse than any other developed nations. Japan had quite a few politicians resign due to corruption. South Korea's last President had to resign because of Corruption. The UK's government was recently caught in a scandal involving a 40 year child sex ring where the police were to afraid to arrest the perpetrators because someone would accuse them of racism. In fact, the UK is on the road to become Airstrip One from 1984. I'm sure if you go into the local towns and cities of various developed nations, you'll find plenty of corrupt politicians who never make national news.

As for religion, it has not been a major factor in American policy probably since the 1990s. The religious right element of the Republican Party is getting old and dying off and the New Right tend to be not as focused on religion. Also, since the Supreme Court declared same sex marriage legal, nobody has really tried to stop it. Also, abortion has been legal in the United States for a good 40 years now and the only real restrictions are on the state level. Aside from that, there's nothing wrong with religion. As long as it is kept out of the hands of government, religion is fine.

As for education, the US had some of the best public schools in the world up until the 1970s. That was when the Department of Education was formed. Needless to say, it has made things worse. The teachers unions don't help because it makes it hard to fire bad teachers and to pay teachers based on performance. The US does have an education problem and will continue to do so until the teachers unions are broken and schools become a state concern again. With that being said, the US still has very good private schools and universities. As far as violence and school shootings are concerned, they really don't happen that often. If they did, the news media would eventually stop treating them as front page news. Believe it or not, school shootings in the US are at a 20 year low. Also, the data regarding school shootings has to be called into question. The FBI classifies a school shooting by shootings that occur within a designated school zone, which is a problem, especially when there was an incident when a man shot himself in his car in the middle of the night outside of a school that had been closed for months. That was classified as a school shooting.

Finally, to answer your question, yes, the US is a developed nation. You can go into the home of an American who makes just a modest living and you can see this. They have stuff all over the place. They have a refrigerator full of food, more electronic gadgets and gizmos than early sci-fi writers could ever dream up, a closet full of clothing and there's a good possibility that the resident of that house may be a little overweight due to the excess amount of food he or she may have access to, especially from convenient stores and restaurants that are open 24 hours a day. And that's the people who aren't all that well off. Even the homeless don't have it all that bad if they play their cards right. There was once a homeless guy in New York City who made over $50,000 in a single year just from begging for change. So yes, despite its flaws, the US has been good for a lot of people, especially people who historically weren't treated well in Western nations. For example, where do the wealthiest black people live? The United States. 

You do realize that the Founding Fathers and Puritans were two entirely different groups of people, right? If Deists were around during the time of the Puritans, they would have been condemned to death.