X3D + standalone Viewer or Blender's game engine?

I need to create a simple room as a 3d model. Therefore a user gets an interface to put in the room dimensions -> this is nothing else than widht, height and depth of a box.

The floor and all 4 walls shall get different textures. These will be chosen in the user interface from a list of thumbnails. The ceiling of the room isn’t important and can be deleted so that the global light can shine in. So I simply could use 5 boxes (4 walls + 1 floor).

Problem: the 3d model shall be created dynamically after the user pressed “OK” in the interface. I made some tests with the X3D XML-based language. Python could create the XML code and also prepare the textures so that one single image will be stretched on a whole wall. There would be 5 shapes with 5 textures and that’s it.

The user must be able to navigate through the room (rotate and zoom is enough). There’s no need to walk through it like in a game but it would be nice. Two questions:

  1. Is it possible to create a scene dynamically for Blender (create a whole .blend file)?
  2. What might be better and easier: to use X3D and a standalone viewer or Blender’s game engine?

I think the X3D method is simple and clean because it can be processed by a script. Problem: I need a standalone player (not a browser plugin) for Windows and Linux platforms to view the model file. I searched all day long but couldn’t find anything suitable. Any ideas?