I'm just saying, that I'm pretty sure this took place in the 60's because when you first spawn in Kino, turn left and you'll see a window. Look really hard and you'll see a 60's Volkswagen (the Hippy-Mobile ).
Now, on-topic:As you may have heard Kino was "Supposed" to be in Map Pack 4 on W@W. I think that the theater was....
1) A brainwashing facility for Nazi Propaganda
2) The Movie theater used for Nation's Pride (Inglorious Bastards pun )
3) Maybe the podium was used by major German officers (Hitler, Himmler, etc.) to show the "glory" of Nazism/Fascism.
4) A secondary "Reichstag" in case of breakthrough but was abandoned
5) Samantha's house-there is a room in the map with Samantha's room!
Kino Der Toten means "Theater of the Dead" by the way!
I think Nazi scientists used this location to test illegal weapons of war on human beings but it terribly went wrong making gas crawlers. Tell me what you think!