Touchpads are great for clicking and scrolling, especially if you set it up to 'click' with just a tap. Alas, it's much worse for dragging, so e.g. graphic design is problematic. Even with dragging via double-tap-and-drag, supported by MacOS, it's a big nuisance, especially dragging outside the touchpad area (which you can do by changing fingers mid-drag).

I've heard good things about vertical mouses: they're supposed to keep the lower arm from being rotated unnaturally, and the hand position seems to be more relaxed. But I still have doubts about pressing the thing, as that seems to be the root of RSI.

In my experience, staying away from computers altogether works much better for the hands than any devices I've tried, which is not good news for a computer geek.