Comment 3 for bug 168926

It apparently already does something like this, but I think it may not always be very intuitive. For example, my system is in English but the locale is Dutch, Inkscape (along with some other applications) regrettably choose to go with the language of the locale, while for me the choice of locale language is pretty arbitrary, I customize the whole thing anyway, and would much rather see it blend in with the rest of my system. On the other hand there is something to be said for following the locale, but still, it looks really weird to have an English version of Windows, (Open)Office, Visual Studio, Thunderbird, etc. and then have an Inkscape that automatically starts up in Dutch.

I just changed the locale to English btw, and it does indeed start up in English now.

As for the original problem with font rendering, it looks like it is trying to use a font that simply doesn't have the required characters.