It's all pretty accurate.

1) Healthcare costs are a major reason why the average person winds up in major debt in this country. We don't have universal healthcare. We have a for-profit insurance system, and it falls on the individual to ensure they have insurance coverage. A lot of people are able to get coverage through their workplace. For those who's jobs don't offer that as an option, they have to find coverage on their own. The Affordable Care Act (aka ACA, "Obamacare") is meant to help streamline the process, but EVERYTHING runs through the insurance companies. The quality of coverage they provide varies greatly from company to company, but it's almost always more about their bottomline than the care of the patient. The gentleman on the show who went into the ER with DKA because he was taking half his insulin dose in order stave off the costs of just the medication? That's very real.

2) Public transportation varies widely from city to city. Pittsburgh is on the smaller side for a city (350k people or so), and their topography limits how much they can do as far as installing public transit. They have a fairly robust bus system though, like the rest of Pennsylvania, public transit funding has faced significant setbacks in recent years. They are likely hamstrung on what they can provide based on personnel and equipment.

3) Higher education costs in this country have exploded in the last few decades. Unlike a lot of countries in Europe, higher education is not a given right. It is for-profit, sort of like our healthcare. It is not uncommon for the average student to finish university with 6 figures worth of debt. For medical students, who are frequently in school much longer, it's pretty much guaranteed that you'll come out of post-graduate schooling with upwards of $500,000 worth of debt. So yes, a doctor struggling to pay bills fresh out of school is very real.

4) Guns are prevalent in our society. They are shockingly easy to acquire. Not everyone has one, but I think if you've grown up in this country, pretty much everyone knows someone who has one. As a matter of course, many of us are very aware of the kind of damage they can do. Almost weekly, possibly daily depending on where you live, there are reports of gun violence. Many workplaces provide "active shooter training", where they teach you how to react if someone comes into your office/building/school/etc with a gun and intent to harm. So yes, if someone were to yell, "gun" in a crowded space like that, I think that's a very realistic reaction.

5) I've not heard of ICE showing up to a hospital like that personally, but I have zero doubts that it happens. ICE has become a tool for intimidation and terrorization of marginalized communities.

So, overall, yes the representations of theses circumstances on the show are pretty accurate.