It sounds like you already know a few examples of the differences between Japanese culture and the culture you grew up in. It's practically impossible to predict and prevent any potentially embarrassing situation.
Being a foreigner will probably excuse you for some of these cases, but as I understand, it is tougher for Asian-looking foreigners, because they are harder to discern from native Japanese at the first glance. Because of this, you might have a tougher time than more obvious foreigners, at least until your gaijin status becomes known.