I agree with your summary except that Rose Tico doesn't seem like a particularly Japanese sounding name to me but I'm no expert. I just played Shadowrun: Hong Kong and I would say it would fit HK maybe? I learned English names are somewhat common in HK accompanying a Chinese (Cantonese? Unsure what is appropriate distinction) family name, though Tico doesn't jump out to me as any suggestion towards any ethnicity in particular; I would guess Finnish or a latin root language if I absolutely had to. Wouldn't make sense for the Kamikaze analogue but I feel that aspect might have been reading too much into it. The rest though I agree with you sounds poorly visualized and nonsensical.
It's the consonant-vowel repeated pattern that resembles Japanese. Japanese is a syllabary, so it's always made up of consonant-vowel sections (other than n, which can float at the end). "ko" is a very common name-ending in Japanese,
examples including Aiko, Akako, Akiko, or
this one girl from an anime, nicknamed "Teko". Th point is, it's very close to the Japanese word structure, especially with a "ko" sound at the end, more than any other east Asian language, which she clearly resembles. There's also the fact that the bomber flown in the movie is directly based off a WWII bomber, even the name is near identical. So the director has an Asian person with an off-brand Japanese sounding last name commit a kamikaze attack in a bomber named after a real one from WWII. It's either deliberately what he had in mind, or he's dense as fuck. Just think - (1) Asian person (2) WWII Bomber (3) Suicide mission. You don't even need the name for this to already be sketchy.
As for the first names of her and her sister, Rose and Paige, are Rian Johnson's choices, basically because he is terrible at names. These do not fit the theme of the setting at all. Nobody in Star Wars should have names that reference things that exist on Earth. Why is she called Rose? Do they have roses in this galaxy?