Well for me very polite form is more easy and i was learned first, formal is little bit more dificult, and i agree Joo Hyung

I think also would help you to listen Korean music and movies. I almost finished my short Korean language programe, my teacher was Korean exchange student and he makes very interesting lessons, in few last lessons we try to sing one song (of course song's lyrics can be not gramaticaly corect, but just for speaking practice and ofcourse its more fun to sing)

I think should be good balance of internal and external. The main point of external beauty is, is that person neat. If person is just looking nice, but empty like a shell, for me he will be interesting just for max 5 min. there are people who looks not very good, but shining from inside, i like that very much.

In S. Korea beauty is everything and many young, good looking people make plastic surgery... and lots of pop idols makes plastic surgery too and what a result, they all looks the same and they think that their faces are perfect and beautiful... but i think they become very boring and not interesting, because their eyes, nose, lips, face shape looks the same, all like plastic doll, no personality... they don't think oh i will work hard and make good result, some of them thinking: oh i make pl. surdgery and i will be more success...  it becomes big maddnes everywhere