I posted some details about the Anthology
here The digital versions will contain all the goodies that we can include digitally (including the journal and the documentary), but they will lack the unlockable items, posters, stickers. (Somebody correct me if I made a mistake here plz
)
But the book really is cool
As far as cut parts - the developer mode is only active in Divinity 2 (i.e. DKS) but you will be able to get areas where you normally can't get. We didn't include levels that were fully cut however.
