It seems well thought-out, and should be nice to try. Was any of it inspired by a certain PS2 video game?
Uhh no. I am a bit older than you think I guess.
This was inspired by old 47 Ronin movies, the series Shogun from the 80ies and a certain Karwansaray demo at Crisis last year
The terrain is scratch built. A how-to is in the making as soon as the building is finished (which is isn't at the moment, but I couldn't wait to test the scenario....) It is certainly not very expensive to make and doable for anyone with moderate modelling skills. The how-to will also feature on my blog.