I am fortunate enough to fly a lot in both USA and Europe. Not that often in Economy, it has to be said, but I do for short hops where there often isn't an alternative. My perception, reading your comments, is that will probably find the English speaking airlines in Europe your best bet, it's not a full cultural match but it is one barrier less.

So that gives you BA, Aer Lingus, a few low cost carriers notably Easyjet, and some smaller airlines. KLM, SAS and to a lesser extent Lufthansa are fairly close to the British Airways operation too, there is no real language barrier; airlines such as Iberia, Air France and Alitalia slightly further off. As an appalling generalisation, AA is quite similar to BA, though BA is both more formal and informal; Easyjet sits somewhere between US Airways and Southwest. All of these European operators are good, professional airlines and I fly on all of them without hesitation.

I also fly Ryanair - they have recently improved their customer service levels, from a fairly low start point, indeed it wasn't able to go much lower. So if you are sensitive to the customer service paradigm, you should only travel on them if your expectations are set accordingly.

BA's crews are among the most mixed, in terms of ethnic origins, of the European airlines, reflecting as it does the diversity of the United Kingdom. There are some US (or former US) citizens working in BA cabins. Ryanair isn't far behind in terms of diversity.

I think I can see why you may have found Korean a bit uncomfortable, I really doubt you will have much issue on British Airways, and nothing that can't be fixed with a generous smile.