What about to add ambient occlusion to the scene? It could dramatically improve the visual fidelity of the rendered scene. There are some libs on the forum or you could go with the babylon.js one.
Finally I must admit, this has potential! Good job and good luck with your product!
Just for the record: The controls in the Editor needs to be improved. I was suffering to get a good camera angle A selectable list of cameras/lights is the first thing you should add.