Turning? I consider the machine relatively easy to turn for its size, I do however need to mucle the machine a bit. If you get the opportunity to handle the machine at a dealer, you will be able to judge the amount of force needed to turn. Whether the machine is running or not, it takes the same amount of force to turn it.
Chute rotation? I did need to properly grease the chute, as Lowes only had a squirt of grease on it. Once I correctly greased the chute and the worm gear, the rotation is effortless.
Grease zerks? There are grease zerks on both augers (left / right)
Bushings / bearings? The friction disk definately turns on bearings (from manual). The auger appears to turn on bearings, but I would check with JD to verify.
Differential? I am hesitant to comment on the robustness of this feature. It works well so far, but I have only use the machine for a couple of months, and have no other machine for comparison. If JD sent you a brochure, the inside of the machine is pictured at the top of the second to last page.
A subtle difference between the engine on the 928 and 1130 other than size is that the 1130 is the Snow Series MAX which has throttle adjustment.