The image property is needed in the EntityRenderer and should be set via the settings.
We will have a number of property lists that will depend on Wikidata. The other ones are for example the ranking of properties and the blacklist of properties. We need a sane and easily editable (by the editors) way to let them change and maintain it.
I don't think making this completely independent of Wikidata is necessary. Easy editability by Wikipedia editors is more important.