I don't know about South Korean knife laws, but have visited Seoul. Should be quite an adventure to live there, or anywhere overseas, for that matter. I think everyone should experience life overseas, even just as a tourist.
If you've never spent a lot of time overseas, particularly in a non-Western country, please try to remember to keep an open mind. Things which seem very wrong, rude, or unfair to our sensibilities are often not seen the same way in another culture. That's why it helps to read about other foreigners' personal experiences, but take what they say with a grain of salt since these writers have their own cultural biases to filter their experiences in Korea.
There are also a lot of social rules and customs there, like in many cultures besides our free wheelin', casual, anything goes Western culture. The rules may seem restrictive and unnecessary, but again, try to keep an open mind. You'll be amazed at how things that seemed really "illogical" at first, suddenly "make sense" to you after you've been the culture for a while.
Just a random suggestion, but if you'll be making friends with the locals, you might brush up on some singing. Singing (aka "karaoke" here) is a common pastime and bonding thing in many Asian countries. It doesn't really matter if you're as tone deaf as a rock, it's the participation and attitude that counts. Besides, everyone will probably be tipsy anyway. That said, it's a real downer when someone flat out refuses to take a turn to sing simply because they're embarassed or don't really know any of the songs. Brush up singing along to anything by the Beatles, Elvis, or the Carpenters and you'll be well prepared for a night at the noreban (Korean karaoke establishment--your group has their own private room. You don't sing in front of a bar full of strangers, like in the US).