Finally, tactile feedback.
What we need is touchpads which 'click' when... clicked. Physically, I mean.
Impractical but not impossible.
The fourth problem is that humans cannot multitask.
We can, however, operate quickly enough to simulate it when our means of operation are close enough to what our brains are adapted for.
Our fingers are one of the best things we have for this job. Hell, look at typing - at any given time, a fast typist is likely to have at least three fingers and the palms of both hands moving.
(but really, rotation is stupid. Can anyone tell me when it would be useful?).
Note: I haven't fully read the video yet, I don't know if I'm responding to what I believe I am. That said:
Rotation is frequently used by artists, as flipping things around can have drastic effect on our interpretation of them.
Also, we're better at moving our fingers/hands/pencils/whatever in some directions than others.
The way to fix this is to eliminate the keyboard and move to voice recognition, or put the mouse in a proper place.
Keyboard can easily be integrated into a touchpad, though I don't know how to solve the tactile feedback issue in this case.
It's likely solveable, I believe.
The problems I have with this concept:
One, finger fatigue. Maybe it's just my hypotonia and underdeveloped forearms, but I know that my fingers would grow tired damned fast from using that thing. Pressing down (typing, mouse button pressing) is simple, but this would involve a large amount of lateral finger motion while applying pressure without using the palms, none of which apply to the keyboard, and all of which is unnatural and difficult.
Two, finger interference. Fingers are big and clumsy and can get in each other's ways.
Three, precision. While it gains some bonus there for being more intuitive an interface, ultimately, our fingers, due to their complex designs, are bad at precise, smooth motions that are easier with our thumbs (trackballs, thumbsticks) or arms (conventional mice), which are designed to move in any arbitrary way relatively easily. Fingers mostly close and open.
For the record, I use a trackball, myself. My input device itself never moves, so I don't have to worry about desk space, I can hold it in my hand and place it in my lap or to my side or wherever I want, and in its default position it is always within thumb's reach of Numpad-Enter and other keys and a minimum distance in general from my keyboard.
None.