Larian Studios Forums Divinity - Original Sin Divinity - Original Sin - General 5% only completed the ending?

You do not need to free the White Witch to complete the game. You would miss some of the story in the homestead without her, but she doesn't need to be free (or alive).

Did Alt identify the loot but not let you to pick it up? The Save Game Editor might allow you to replace it (which may or may not work with the elemental forge).