I wouldn't criticize the keyboard and mouse set up until you configure it properly. Much like you're saying that you think a properly configured Wii-mote is good, your points don't make much sense to me if you're not trying to configure the controls to fit your play style.
For example, I have no idea how your fingers can slip off the keyboard unless you tried playing with the keyboard angled up by the two stands on it (something I've NEVER done while playing on a keyboard). If that is the case, have you ever thought about putting your keyboard level with the desk? Also, I have no idea how your hands get tired on the keyboard, it's usually my mouse hand that's hurting after a while because I like to be aware of my surroundings and I look around a whole lot (and I've been using the computer for most of my life now. I'm getting old, what can I say?). I understand you may be confused with the keyboard because of the buttons but again, try to configure it based on how you play. I used to play using the arrow keys on the right side of my keyboard for years because the arrows keys felt easier to recognize and when I made the switch to wsad, there was no confusion.
Even more interesting is your mouse arguments. Have you ever tried to, you know, turn up the mouse sensitivity to lessen the distance you have to move it across the desk? For example, in Portal (or any source based game), I have my sensitivity set to 5. In Counter-Strike (or Half-Life based games), my sensitivity is set to around 12-14 (depending on how I'm doing that day).
Honestly, my hand hurts probably as much using a Wii-mote with waggle/'motion sensor' controls that require you to do things like flick (ect) the controller to do extra things. Again, I don't understand your motion argument because I can either assign a button for the motion controls you mentioned or I have my mouse sensitivity to my liking so I have no need to do a quick turn when I can turn that fast on my own.
I'm not saying the wii-mote is bad, but I just don't agree with your arguments.
