Fine. It is a rear drive as an assembly. It is a ring and pinion as the components. There is no difference between the ring and pinion in a motorcycle or any other vehicle and is a differential. Call it whatever makes you happy. I'm just happy you knew what I meant.
Handlebar issues are totally personal. It all depends on your height, arm length and a number of other personal issues. Handlebar sweep (angle) is mostly dependent on you shoulder width, but also on your personal comfort. I have wide shoulders and need a straighter handlebar. Same on my motocross bike. It is all very personal.
If you are happy with the stock gearing, then I am very happy for you. Obviously, I was not. Now I am. Have you owned a Gen l? Your info shows a Gen ll which is over 300 rpm lower than a Gen l due to Yamaha recognizing the issue and changing the transmission gears to higher ratios. All they had to do was pick the RSV rear gears off the shelf and put them in the FJR. My 1st gear was so low it was useless. Now it is normal.
Happy riding.