Hey @Wulf,
Can you add a command for the Users to turn the Translation on or off for himself? (A permission can do the same thing)
Some Player like it other hate it. 
I think its a nice thing but some time its anoying if it's "translate" german to german as example.
At this point it would be great if you can turn it off.

Maybe its possible that messages in the same language dont get translated. (Or a extra option like "silent" mode so if you are german messages from other german people dont get translated)

But props to you (if this is the right word :D ) i like the plugin and i think with some adjustments it would be very very great

Languages shouldn't be translating if they are the same language, if they are, then their language set on the server for them isn't the language they are speaking. I don't see a need for a command in this case, they just need to set their language properly in order to not see translations of their own messages.