It doesn't matter if you do all the error checking in the world, or if you have the most beautiful graphics, if your site or application design isn't usable, it's not going to do well. Get input and advice on usability and user interface issues here.
I'd bet its the Chinese localization that's causing the problems. Change everything back to Western European and English, and it'll hopefully clear up.
Real programmers don't comment their code. If it was hard to write, it should be hard to understand.