Is there a possibility to draw a text to dump var on screen
In the next release, probably this weekend, you will be able to use Overlays which is Ogre's way of handling 2D graphics.
It's basically a kind of "noninteractive" gui which you define by scripts just as the materials.
They are very easy to use and I will provide some samples on how to use them.
Regarding the problem you had with textureshadows.
Try adding
GameObject_MeshCastShadows(Room,false)
When using Textureshadows, objects recieving shadows may not cast shadows.
TEXTURE_ADDITIVE also requires that the room material has lighting enabled which is doesn't by default.
You can change that by setting 'lighting on' in the room.material script.