I would like to know how to go back to stock from the kitkat German version.
I was thinking to flash it via odin but I dont know if knox will let me flash.
Don't know about knox but the new bootloader prevent firmware reversal so you can not flash it using odin on pc. However if you want to downgrade u can use mobile odin to downgrade as it does not flash boot loader and thus can downgrade your note 10.1 to 4.1.2
But again the bootloader will not be downgraded nor till now any method has been discovered to downgrade it. I my self downgraded using mobile odin and mine is working fine.