Hey Philip,
I can help you out with that.
Regarding knives, everything is legal
except:
- all pushdaggers, butterflies and automatic knives that come out of the front
- automatic knives that open to the side and are
longer than 8.5cm
- any
double-edged automatic knives
- any automatic knives with blades which breadth is
less than 20% of the knife's length
- automatic knives which do
not have a continuous back that tapers towards the point
I know the last two points sound somewhat weird and in all honesty I don't know where those rules historically originate from, but it's the law.
So basically no pushdaggers and butterflies and no automatic knives > 8.5cm and you are fine. Also note that any daggers are considered "weapons", which means you are not allowed to carry them on public events and such. On the funny side it would be perfectly legal to run around with a claymore bi-handed sword on your back. Just don't expect to really get away with it.
Just stick to any manual knife and you are fine in Germany. Guess we are still on the liberal end of the knife-spectrum here.
-Connor