Togusa is the squad's resident Badass Normal, aptly demonstrated in a scene where he easily dispatches a hit squad sent to kill him in the middle of dinner. Given the dystopian nature of the setting, it's easy enough to guess that most cops would develop such keen survival skills even without the presence of cybernetically enhanced gangsters and assassins. Or at least, the ones that didn't wouldn't become middle-aged cops. More to the point, Togusa would have to have such survival skills to become an experienced cop with his natural body mostly intact, without apparant need of replacements or upgrades.
The Major is shown using a medication that's applied via the ports at the back of her neck, and it's mentioned as being something that prevents her brain from rejecting the cybernetic body. Since it's an organic body's immune system that causes tissue rejection issues, this seems to be a strange excuse, or possibly a facet of human-brain-to-cybernetic-body sci-fi medicine. It's then revealed that the "medication" is actually a memory suppressant, so the "anti-rejection" excuse is clearly a lie—or is it? One could say that the Major recovering her true memories could cause "rejection" in the psychological sense...
It's not to prevent the body from rejecting the brain, but rather to prevent her brain from rejecting her body, in the sense that her memories would reveal what Hanka did to her in order to put her in that body. Assuming she sees a distinction between herself and her body, of course (that question being a major driving theme of the franchise as a whole).
The casting Race Lift controversy surrounding this film is interesting in the context of what happened to Motoko Kusanagi in the film itself. A Japanese girl taken against her will and forced into the guise of a Western woman, her entire history rewritten to reflect this new background. And who are the people specifically responsible for this? A pair of corporate Westerners (an American executive type and a European scientist) and the faceless suits in the company's employ. Meanwhile, the Major's team, who come to her aid, is lead by a Benevolent Boss who is Japanese to the point that he never speaks any other language and represents the Good Old Ways. The film's production controversy serves as a backdrop for the Major's own history in this iteration.
Aramaki is implied to be very old school, he speaks Japanese (despite everyone else speaking English in a very multicultural future version of Japan), carries a revolver, and in his two fight scenes, takes out his opponents via Quick Draw. Given that Cyberpunk is already a blending of genres, Arimaki is the setting equivalent of an old samurai, defeating his overconfident but outmatched foes in the setting-appropriate version of a Single-Stroke Battle. A cowboy's revolver may as well be a Samurai's katana in a setting rife with cyborgs and androids.
What happened to cause people of Western European heritage, more specifically Americans such as the ersatz Killians, to become refugees?
The manga makes reference to a WWIV, so it's possible that's in the backstory of this film as well.
The backstory of the manga is that the United States lost 1/3rd of its territory as a compromise to end the Cold War, then again list 1/3rd in the 2nd American Civil War. Add World War 3 and 4 into the mix, and it's easy to see how westerners could be refugees.
