MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I do not handle the backslash. It is there. The only way how to deal with it is to use motors that do not backslash too much, keep reasonable tension of the belt and rely on the resistance of linear bearings on precision rods that will not let the carriages move freely but only when you turn the motor, but still are slippery enough so these motors will suffice to get them moving. As they can move in X and Y axis only at low speeds, the backslash is not exaggerated by inertia, too.
So it will probably not show up. Rectangular shapes are just fine, there may be a problem with iregular circles but it is still not clear if it is due to backslash or some other issue. No special gcode generator is needed. I use Slic3r. You may try to use Repetier firmware with backslash compensation, but i have no personal experience with it.
Still, this printer is not made for high precision prints for sure, but it will do the job. You can see some videos on youtube. There are not only my examples so you can be asured I did not made it up or manipulate the results. ;)