Germans are kinda.... offended by 3rd Reich Symbols, especially the swastika. Showing these is much worse than nudity or alcohol. So dont expect it.
If you want the most historically acurate "flair" try Op. Monsun (SH3 revived, simply said, but awesomely done). Ships flags are showing the swastika there.
RUIM puts Nazi-symbols in your crews uniforms (install the eyepatch on top of it). For german sounds try Spaxx and Poulsen on top of that. Thats almost better than Highschool-german-lessions.
BTW, germans say "Jawohl (Herr Kaleun)".