If the characters offend you, can someone please WHY they are offensive? Not WHAT is offensive, since people keep saying that the characters and their situation is, but I honestly don't understand WHY that should offend. Your ignorance is just unbelievable. You don't understand why it would be offensive? When people comically portray a specific group of people by using a stereotype, it's offensive obviously to the group that is being made fun of.
I think it's even more terribly offensive to see white actors performing those two roles with thick Chinese accent. But if they don't have that dialect, it wouldn't make sense. Therefore in my opinion, the show shouldn't be done without 2 Asian actors.
And in this case, I think race/color does matter, just like in Ragtime, The Color Purple, or Miss Saigon. Those two characters ARE obviously Asian, no matter how small the part is. It wouldn't make sense to cast nontraditionally.
"Hey, you! You're the worst thing to happen to musical theatre since Andrew Lloyd Webber!"
-Family Guy