Nevermind about the debug method as it's old and probably outdated now. You can just change the encoding of the txt or file to utf-8 and you should be able to read it on the kindle. The font used is a little faint though. I had a hard time reading chinese texts with the default font but that's just my preference. Without using any hack, you're able to read chinese texts and files.
Well, you can uninstall the hack but to be safe you can choose not to do it. Warranty's for a year. Kindle's screen is quite fragile... any hard knocks on the screen may cause lines to appear on it, so a cover is definitely needed.
I had been using mine for nearly a year without problems. Only recently i noticed a black line blocking some words near the bottom of my screen and i got it replaced. Screen's definitely the fragile part.