I def think Tsai and Qiaqia are fine as is. Chiachia does not work for me, it does remind me of pandas! Or some pokemon type of thing. Maybe because I have done a lot of work throughout Asia (including China and Mongolia) I didn't struggle with them at all, but I agree with anef's comment, its part of reading fantasy. Even if the reader's interpretation isn't the correct one, its just a name that they say in their head, and I somehow feel that the spelling of the name is just as important for the identity of the character and the world you are building.