[Rumil]

Just a quick comment,

The Mouth's threats of Frodo's torture made me think of Hurin's torment by Morgoth (not necessarily, naturally, but maybe). Especially the plan to release him when 'changed and broken'.

Perhaps as well as physical torture (see Gollum's fingers!) there would be mental torture - restrained and made to watch the fall of the West, death of friends and family, destruction of the Shire - in a Hurin-like fashion.

Then the mysterious 'Houses of Lamentation' which seems to be some sort of spiritual torture. If Gordis' proposal is correct and Sauron can restrain the souls of mortals from 'The Gift' in some way, then does this not explain the 'Necromancer' tag?