IMHO, being a member of the Hitler Youth (and the German Army, if that comment is true) would be a disqualifying factor. Whatever the reason. I recognize the range of pressures and cultural factors that drove people to such membership, and I don't claim that anyone who was, say, in the Hitler Youth is per se an evil person, or even that he was ever knowingly a Nazi sympathizer. Nor am I saying that all such people are beyond redemption. But it's a long step from there to being the representative (embodiment? I can't remember, it's been decades since Catholic school) of Jesus Christ on Earth.
If that means that a generation or two of Germans is disqualified from the Papacy, I view that as no big deal. There's other jobs.