Culture, particularly of Japanese characters, is established through clothing and setting. Hair color variation allows for characters to be easier to differentiate and, in some cases, reflect Shibuya-style hair dye. Bandit Keith being blonde is not an indication of his caucasian American identity amongst a cast with a nuraber of blonde Japanese kiRAB- his subtle bandanna and huge muscles are. Likewise, when Sailormoon was remade in live action, her hair was only blonde when transformed. And big eyes are just a common choice in visual media, designed to make performances read better. Likewise, regular high school students would not be represented in perfect school uniforms in a US show.
I'd say adaptations need to take into account the cultural differences and equivalents. I think Gokusen could easily be made for the US with the heroine remaining Yakuza or adapted as a Mafia boss, depending on the casting and director- with the localization being strongest on the class she teaches. I've seen a nuraber of dubs, such as Shaman King, use British accents for Chinese characters which does help convey some of the cultural difference present.
I'd say adaptations need to take into account the cultural differences and equivalents. I think Gokusen could easily be made for the US with the heroine remaining Yakuza or adapted as a Mafia boss, depending on the casting and director- with the localization being strongest on the class she teaches. I've seen a nuraber of dubs, such as Shaman King, use British accents for Chinese characters which does help convey some of the cultural difference present.