Wow, this is so cool. I can understand where some of those "translations" come but others are all gibberish to me.
"Backstroke of the west" probably comes from the Chinese translation of the name "Sith," which contains the word "west" (which is pronounced "shi" in Mandarin).
The triple "Good good good" probably comes from a common phrase "hao hao hao" (literally "good good good") which meaning is some sort of agreement, like okay.
The "R2, do you is fxxking" is even funnier because in Chinese "what are (you) doing" contains a word which also has the meaning of "fxxking." Of course, no one should confuse with these two.
I don't know how the "big" part came from, but in Chinese a "supervillain" uses the words literally "big bad egg."
The "elephant" in various places probably comes from the fact that the word "elephant" in Chinese also has various other meanings like appeances or facts.
The last "do not want" probably came from the literal translation from Chinese "no."