This design doesn't reduce any sideloading on the CIM shaft. Bearings only provide significant radial support forces that you can rely on. You're still using the bushings in the CIM for support.
Now, if you're really concerned about sideloads (I wouldn't be, but I don't know your specific applications), I'd support the wheel on either side with a bearing (like in a typical FRC drivetrain), then couple the wheel to the CIM with one of these that allows for shaft misalignment:
http://www.mcmaster.com/#standard-sh...lings/=10un04v
That way you don't have fighting with misalignment, which would add friction that both reduces max speed, rev up time, and longevity of your device.