Jerzy
The book is published at a -normally- well reputated, but a little bit conservative publishing house.
The sub-title of the book is "Deutschland im Bombenkrieg 1940-1945" (Germany in the bomb war 1940 -1945"), so actually Poland isn't a theme of it. (And it's not about Germans doing the bombing but Germany detroyed by bombs - the different air wars are neither a theme.)
I don't really understand the last part of your response.
I am born in a small town, which was just (severely) bombed twice: both times hundreds of refugees (from the Ruhrdistrict) died in trains. People weren't forced to leave the towns, they went volunatrily.
Klemperer wasn't a participant at Wannsee at all.
You can see all participants and their biography here:
http://www.ghwk.de/engl/catalog/cateng6.htm