What is it you're doing when SketchUp crashes?
FWIW, when I model for 3D printing I set Units to Meters and model as if millimeters are meters. This allows me to model fine details and to create smoother curves. The slicer I use imports .stl files as millimeters but I export the .stl with model units (meters). For examples see my thread on 3D printed screw threads in the 3D Printing forum category.
Keep in mind that adding a mesh from a an image like the brick texture I used adds tons of geometry. This can slow SketchUp quite dramatically depending on your computer's CPU and GPU. You might get frequent messages of "Not Responding" which normally isn't a crash. Just that SketchUp is busy and won't respond to further inputs from you until it is done. It might be that you'll need to break your model up into smaller sections and assemble the printed modules when they are complete.