About the lighting: I haven’t tried this but I guess a single sun-lamp with disabled shadows should be the closest match to Qubicle’s lighting. If the dark side of the models gets too dark then raise the ambient light (probably has to be done on the materials, but if you’re lucky the lamp or renderer has a setting).
About the rules: The rule about no post processing is there so that people who bought Qubicle shouldn’t get an advantage by exporting models. Since this is done entirely in Blender, which is a free program that anyone can use, I think its ok. The last version, that “skips the cool stuff”, should definitely be ok. 
For future submissions done in Blender we should probably set up some rules though.
Example: No perspective, no shadows, no reflections, no transparent or glowing materials, one sun-lamp (if that works), all voxels should be aligned with the x-,y-,z-axis of the scene and appear to be in the same grid.
Also, props to @Xavion for mimicking Qubicle in another program. That sort of stuff can get really painful. 
Edit: Really wanted to make a submission for this week but haven’t had the time. I have a nice image in my head. Maybe I find the time tomorrow. Otherwise it goes on my list of Qubicle-art-to-do. 