Eric,
I've taken the two of your sentences that mean the most to me.

I feel very strongly that the Holocaust was, as you say, a uniquely horrific episode of the 20th century and cheapening it is absolutely the last thing that should ever be permitted to happen. It and the name Adolf Hitler should be retained vivid and used only for the absolute evil that they unleashed upon the world and which they uniquely and alone signify. They should not be allowed to become terms for merely bad things that happen, or to pass into general use in the language merely as derogatory epithets.

Does the Verhaeghen book add something to the Holocaust literature? Absolutely not! Not at all, not from what I have read, nor especially that I know directly from contemporaneous news reports in the US as the camps were being opened during my childhood, nor from reading since then. I don't believe that heightening consciousness was his intention, unless for younger people totally unaware of those abysmal events. But I find that hard to credit. My view is that he was writing a novel with fictional characters set against more or less realistic background -- and with respect to the Holocaust, not realistic or terrible enough.