> Also, I think in German it's very common to string together words like that to form longer words. Are there more languages with that characteristic?
Yes. All of them.
> Can the same argument be supported at the word-level also?
Here it depends what you mean by "the word-level". "Words" are commonly taken to be compositionally opaque. Compound expressions are not compositionally opaque and are not "words" in this sense.
Yes.
> Also, I think in German it's very common to string together words like that to form longer words. Are there more languages with that characteristic?
Yes. All of them.
> Can the same argument be supported at the word-level also?
Here it depends what you mean by "the word-level". "Words" are commonly taken to be compositionally opaque. Compound expressions are not compositionally opaque and are not "words" in this sense.