Wow. Thank you for all of the German help, luinrina!
Once again, I have some more things that I need help translating/correcting...
Deutsche Zauberaufgabe-Gruppe: I believe this is "German Wizard Task Group" or something like that. This is the pre-Grindelwald Auror-equivalent group that was liquidated in 1933 and replaced by the Mitternachtsmannschaft. Before the purge, the members of this group were called Dzaggers, formed out of a skewed acronym: Deutsche Zauberaufgabe-Gruppe.
Zauberereich-Kanzler für Magie: I'm not too confident about this translation, but this is Grindelwald's title/position, the "Wizarding Reich Chancellor for Magic." Please correct me if I'm wrong. Also, if you have any ideas of your own on what Grindelwald's title should be, that would be lovely.
To return to the Schnell! vs. Schneller! issue, how would you use them as short, barked command? Just scream "Schnell!" if you want someone to go faster, and "Schneller!" for them to move even faster? Or is one favoured over the other when it comes to ordering people around?
And lastly, how would you say as a command, "Muggles, out!"? I just think that "Mehrere Muggel, heraus!" doesn't sound right.
Once again, thank you for helping me think up the minute details for my story!
Tim the Enchanter
PS: Oh yes, I forgot something! Would Grindelwald's empire use Galleons, Sickles, and Knuts as currency? The Harry Potter books never say whether those coins are specific to Britain or if they're used throughout magical Europe.
So, assuming that the Zauberereich used its own currency, what would you call it? The Zauberereichsmark? (and would it be decimal based?)