i know otaku is someone who likes the japanese culture, but at the same time, i am just not so sure about the exact definition/ criteria of being called an otaku. just how obsessed you have to be to be called an otaku?
It's for you to decide yourself. If you want to get technical (and weeabooish), otaku basically means nerd in Japanese. You could be a hunting otaku, a football otaku, an anime otaku, whatever. If your hobby is anime or manga, you are probably an otaku in American standards.
>>2 is right.
Weeaboo is the best term for a foreigner who obsesses about Japanese culture, the only term really.
Otaku actually expresses your love or fetish (non sexual) for a certain thing. So you can be an anime otaku, movie otaku, metal otaku, sport otaku, cook otaku etc. Though it has taken a bad meaning through the years because of the kind of people that have those obsessive love about things, so it can be considered bad in japan as bad as if you called someone a geek or nerd in US. Look here for more info: http://en.wikipedia.org/wiki/Otaku
Is it Otaku if it's a useful skill or hobby? I mean, cooking for example. Maybe being a gourmet can be an otaku, like being able to distinguish different types of rice by taste alone, that's pretty weird and obsessive. But if you're a passionate chef, and make a living off of it, does that make you otaku? I always felt that in order for it to be otaku, it not only has to be passionate and extreme, but also, useless.
It just has to be passionate. If you can also make it useful then even better.
"Otaku" = life failure