First-time poster here. I just a follow-up to this topic. I recently went through all these issues with my new iPhone 4s here in Korea. Thinking I needed to get a Korean iTunes account, I proceeded down that path. It was delayed a week or so, because I had to obtain a credit card in my name (a debit card in my name wouldn't work, nor would a credit card in my company's name). During that time, I was impatient, and took a chance and started a USA-based account. Bought the apps I wanted, and tested with a purchase at the iTunes store (I am a Apple and iTunes newbie). Everything worked...
Finally my Korean credit card arrived, and I was pretty stoked to test out the Korean iTunes store. I was especially interested in being able to buy Korean music legally. It's surprising how quickly CD-s go out of print here, and often it's next to impossible to buy older music. I tried and tried, and I coudln't figure out how to access the Korean iTunes store, although I was able to buy an application using my Korean account.
After LOTS of research on the net, I figured out the reason. KOREA DOESN'T HAVE AN ITUNES STORE! (that could be the subject of another whole thread). Anyway, I really wish I had realized that up front. Oh well, I'm up and running, using my USA-based account, technically, agaisnt the terms of service, as I understand. The Korean account ended up being basically useless to me, except that I now have a new credit card in my name.