Re : Being mistaken for a tourist.
I have it the other way around. Both of my parents are Japanese so I obviously look Japanese, have a Japanese name, etc.
Yet, when I'm in Japan, people consistently assume that I'm Japanese.
It's annoying but I let it pass because I'd do the same if the situation was reversed.
Oh yeah, on a different note, there was a time when I was living in Japan for a few months and fed up with the monotonous nature of Japanese society. I'd always see a few caucasian English speakers on my commute to work and I'd instinctively give them a smile or a quick greeting. I wondered why they never responded until I realized that I looked like one of the other 127 million Japanese citizens to them.