Feel free to pick my brain anytime! Though some of my information will be long out of date -- it's been quite a few years since I lived there.

As for travel to Japan, I took the ferry from Busan to Shimonoseki, then traveled by train (and sometimes hitchhiking, though I *really* don't recommend that!) to Hiroshima, Osaka, Kyoto, and points along the way. It was pretty economical and loads of fun.