I use ein 7 german Version. There is no problem with language or Charaktersets. Even Chinese Charakters are shown using URT-8 or unicode.
Imside gramps I Cannot tell you which characterset is used. Yesterday I exported to cvs and I think it was ansi but all the äöü were wrong when i opened the File in xlsx. I imported My database when I started with gramps from from an english System, genopro, which I still use parallel (I keep data in gramps and gedcom export into genopro) as I can better compare different families visually