I speak as SLF who has lived in Korea to 10 years and address only that part of the OP's question that I can - social life.
Ex-pat KAL crew seem to be lodged around Incheon airport. There is very little in that area that might appeal to a western ex-pat. That said, the bright lights of Seoul are barely an hour away and there is pretty much anything one might be seeking, if not so up-front as in other Asian cities. There are many international restaurants of good standard, especially in Itaewon. There is a Hash-house harrier chapter, football and rugby clubs if they appeal. In winter, there is skiing not far from Seoul.
Now, perhaps reading too much between the lines, there are also many women who speak tolerable English. (And no, I do not mean ladies of the night, although they of course abound).
The food takes some getting used to. Some never do.