In our era, you need to be both more open yet focused than in the past. We live in a cholent of a society, both frum and general. In the office, there are Chinese, Indians, Albanians, you name it. That's not how things were 50 years ago. In my shul there are Sephardim, Hungarians, Israelis, Germans, Midwesterners, Brooklynites. You can't say my way or the highway anymore. It doesn't matter if in Frankfurt one frum community didn't say hello to the other. That won't work today because we are all mixed together in families, in schools, and in shuls. As R' Miller advises often, you have to get along with people. Moreover, the American personality is more open and accepting.
Yet, at the same time you have to maintain your focus. If you are not mystically based, the mystical stories can confuse you if you take them too seriously. If you are not punishment model based, same thing. In the Hirschian model, the rabbis don't dictate policy every 10 seconds so when they do you listen. You can go crazy if you have the Hirschian mindset and step into a Haredi shul, unless you know how to take it. So you have to be aware of the different styles that are out there and how they differ from yours, so you'll know how to take them.
If derech eretz is fundamental to your observance, by that I mean honesty and politeness and order, you have to be careful in communities where that isn't so important because you can get influenced and lighten up on a key avodah for you. And then you are lost as you try to base your day on values that are not core for you.
In Haredi communities, staying away from society is core. They pride themselves on that. People will brag that they have no idea who Shakespeare is. They tell you with glee.
That's fine. I'm not telling everyone how to live. I pride myself on worldly knowledge, but also on being able to separate out the bad and keep the good. Very different approach. That approach is bad for some, good for others. Each person has to find the one that works for him. In our society, you can't simply do just what people around you do because there are all kinds of people around you. It's not as simple as, I'm from Hungary, I do everything Hungarian style. But you don't have to condemn the others. Remember we are American Hirschian TIDE. Americans are more open than Germans, more tolerant. Like that other Germanic people the Dutch. Torah is eternal. TIDE changes in each society.