Sin City is a completely ficticious place, and you find yourself accepting the weirdness you see as part of this ficticious World, perhaps because you know in your heart that, while graphic, the violence is all make-believe, which allows you to experience these sometimes horrific scenes vicariously, with the amusement that was intended by the Filmakers.
Sin City bears NO resemblance to K Ill Bill, a movie that celebrates gore and violence for shock value, and is Mr. Tarantino's homage to the violence of Asian Kung-Fu/Karate films.
If you go to Sin City and simply cannot stand the violence, I will ask the Filmakers to refund the price of you ticket myself....

your pal,

bw