[Answered ]-Django admin: how to edit two models with indirect relationship on the single admin view?

Instead of using the Item model, you could probably use generic foreign keys so that your models become:

Translation
    item (generic foreign key to Article, FaqCategory or FaqItem)
    lang (language code)
    title (string)
    body (string)

Article
    published (datetime)
    visible (boolean)
    item_id (foreign key to Item)

FaqCategory
    item_id (foreign key to Item)

FaqItem
    category_id (foreign key to FaqCategory)
    item_id (foreign key to Item)

Then, you can use inline model admins.