I think this module could be quite good for a lot of different sites, especially if you get to choose the categories you want to add for each character (depending on the kind of site you are building).
I haven't tried doing this, but it seems that you translated all the core (system module) language files, but not the module ones.
Inside each module (/modules/newbb/language for example) look for the language folder, and then in there should be the language files. You may have to translate each module on their own.
Perhaps someone that has done this can help you...