|Imperfect of Sein for passive voice|
First off, your info seems very thorough and organized :)
But in the Passive voice section, it says for plusquamperfekt to use form of war, and yes that is correct but instead perhaps of phrasing it that way maybe say use form of sein in simple past tense (imperfect). But I did know what you meant, it was not confusing to me, just thought perhaps others would find this of helpful use.
Again this is not so much a mistake but more like an alteration.
Thanks so much!!