yes I'd appreciate any help!
You usually translate the language strings on transifex and I'll pull in the languages to the source repository of FlaskBB from time to time (which, I haven't done in quite some time when I think about it..).
If you tell me you username (you can PM it to me) I could add you as the language coordinator (translate, review and manage the language team) of the german language.
Regarding the spam on the forums, I know it's really annoying and I am usually visiting the forums on a daily basis as well. I haven't found a way to prevent those spam posts yet even though I have activated the reCAPTCHA and account activation feature.