I Think there should be a decal editor and a model editor/texture editor.
Decal Editor:
Will allow the placement of 2d textures over models that do not move, such as walls. This will allow to break up repeating patterns and make a world feel more real. The Decal Editor will allow you to import a Decal, and change the size, opacity, and light levels of the decal shown.
Model editor/texture editor:
is where you can see your model with all of its textures and effect its properties and see what happens in Real Time. This will allow you set a scale for your model/change rotation and make sure all your textures work and if they effect your model in the way you want to "QUICKLY".(You can do this but it does take a long time)
An Alternative to this would be to add a form of reloading all the Assets in FPSReloader as currently the only way to do this is by restarting the program.
RAM 8 GB
i7-4770k CPU 3.50 GHz
NVIDIA GeForce GTX 550 Ti