Translation of Patches and Library Objects for International Versions

They will work, but they will be in English. All the input files are just text files, so you will be able to edit them in any text editing program.

So will it then be possibel to play a 'german' version ALL in english by configuration (to avoid a mixed environment) or, say, in french (for educational purposes)?

No, it won't actually be a configuration option, but if you can get the data files for different language versions, you can switch between them easily just by changing folder names.

For example, if you're in America and you get one of the french players on this forum to send you his translated files (or maybe SF will make them available on their website) you can save them in a folder called French Data.  Then when you want to use the french files, rename your current Data folder to English Data, and rename French Data to Data.   This will work except for the few areas where there is hardcoded text.

Oh-oh... I see where this will lead: Soomer or later we'll have a klingonian version of galciv. LOL

Finally GalCiv arrived on the german shelves

Before trying to install first the german version from the CD &
then the latest patch, I want to clarify a bit:
Are there any unpatched text files which won't be overwritten by the patch
(and so remain in german)?
I want to avoid a mixed environment & ask:
Can I obtain those files from stardock?

I don't know if you have a spanish version or if you plan to create one, but if you need any help in translating from English into spanish, let me know and I can help.