Yes, the lightmaps thing will be very difficult to realize, maybe a little easier if you have purelight, but not sure if it is worth that cost.
I would import the models into blender, add a second UV map and use lightmap unwrap, blender has already an automatic function for that, it will unwrap the model for use with lightmaps.
Then I would place lights where lights should be and then bake lightmaps, but then you would face the problem, that torque needs that lightmap in each material slot as lightmap, this system only works well if you use one atlas map for the whole model, otherwise it will be a pain.
So overall it may not be worth the effort.
I tried lightmap baking the ambient occlusion into my buildingsite map, but then found that the Torque lighting with SSAO gives a decent result.
First I would try to replace the many blank surfaces with actual textures, it may give the greatest visual improvement, you have many plain white or red surfaces, they are pretty aggressive to the eye.