on the whole you relax and have fun. The Korean education system is the harshest/most competitive in the world... LITERALLY, but not in college. The difficult part is actually getting into college, but you're expected to lead a balanced life that leans more to partying than anything else.
To be honest, it's not so easy anymore to gain entrance. If you applied 5 years or so ago things might be different, but due to Korea's recent gain in cultural/pop-cultural awareness throughout the world, many bright people are studying/moving to Korea. Naturally, the competition has increased substantially. If I may be a bit blunt, your grades are fairly sub-par and your activities aren't particularly impressive either, and knowing English or your resolve to major in English won't be a major consideration especially considering that per capita and BY FAR Korea is the world's largest "importer" of foreign English teachers. You're not just competing against Americans/Australians/Canadians, many Europeans (germans, french, etc...) are just as proficient in it as you are.
I think you should certainly apply though just for the experience.
Here's what I think you should do, just go to college, do well in school, and apply for the international programs in Korea and Yonsei university by your sophomore year, and join a Korean club to boot. With a 3.5 or so you should definitely be competitive and you should mention your prior application to show your improvements and your continued interest in their program.
You should definitely go to Yonsei if you can though. They're surrounded by a million different restaurants, cafe's, bars, live houses, etc.. it's a blast.
P.S. I think you have the wrong attitude. Perhaps I'm interpreting it incorrectly, but when you say, you're not going there to learn Korean, do you mean in general? The Korean language is considered to be among the most scientific and easy languages to learn. Unlike Kanji or Chinese which takes even its residents nearly a decade to become proficient at, I would probably call you borderline retarded if you can't read Korean in 2 weeks to a month.
Good luck!!!!