My short answer: No. Yes.
My long answer: No, there are generally no research requirements and teachers at Korean universities are more along the lines of "English Teachers" or "adjunct lecturers" than full-fledged "professors." There are some exceptions of course because there are foreigners with PhDs who are teaching in their field of expertise and those people would definitely have different expectations.
Teaching in a Korean university provides an excellent work-life balance. It's more of a part-time job if you don't do any overtime and just work the standard contract hours. Most people work 3-4 days/week and get anywhere from 2-5 months vacation.