Ash,
If it's an area you havnt tried yet, I have some valuable input regarding this.

I'll post some pics in a bit to illustrate what I mean. The main thing is to set "Speeds and Movment".

There are 2 settings. One for "When I move fast" and "When I move slow". Set these values at more extreme settings with "When I move fast" set to move the cursor fast, And "when I move slow" set to move the cursor slow. Then the ball is set in the palm instead of fingers. With just a "FLICK", the cursor can shoot all the way across the screen. Yet if you "MOVE" it, the cursor moves with slow precision. WHat you eliminate is "Click and hold" to "Scoot, Scoot, Scoot" so common with mouse operations (This is where most mouse stress comes from) Buttons that do the "click and holding" for you.

Not trying to get you off a tablet, just to replace ANY mouse work you may still need to do.

These settings can be found in regular shaped mouse drivers also, the benefit with the ball is the placment in the palm instead of the fingers. It allows you to just about "Relax" your arm and make very little movment or "Tension" in the arm, hand/wrist, fingers. Clicks are accessible with say the side of the thumb as a tap down.

Anyway, I'll see if I can get the wife to help with a short vid or something to illustrate so you get to experience what benefit I'm refering to.

Good Luck, talk to you later,
Burr