>Is that true that a civilian can't enroll a military university to become a Bundeswehr officer? I.e. you have to enlist as private, serve some years as a grunt, may be get an NCO rank, and only then you'd be suitable for becoming an officer candidate?
Not that I know. It might be possible that you need to do some 'basic military service'.
Ok, I just looked it up: When you start your officer career at the Bundeswehr you are gonna do a 'basic one year military training' (at a officer's school, so the plebs are somewhere else I guess) and then you start to study at one of the two Bundeswehr universities (Munich and Hamburg)
Have a look here for further information: https://www.einstellungstest-bundeswehr.de/bundeswehr-karriere/bundeswehr-studium/