Certainly it should be an option to have a virtual keyboard on the touchpad or a dedicated physical keyboard. To have such a capable touchpad and deny the possibility to use it as a keyboard would be dumb. To force users to use a touchpad instead of a keyboard if that was their preference would be dumb.
One thing that I find overly laborsome in the current O/S scheme is accessing the file structure. The video seriously misses the mark by showing an example File>Open>Select>OK pattern. That concept is extremely out of date with current O/Ss preferring either a application-file association or a simply drag-n-drop onto the application space. File>Open could and should simply just be removed altogether. The idea of a touch-brings-file-system-navigation-overlay file-dragged-onto-application (or simply double-clicked) is extremely appealing. Things like not being able to drag files onto taskbar buttons is hilarious in

.
One way I would expand on the ideas in the video is to extend the lateral linear structure concept in another dimension. Having several local lateral structures separated vertically could allow me a more task focused approach. For example I might have a row of photoediting software, a row of web browsing, and maybe a third row for MS Word. Currently I do things like this by having 3 Firefox windows open and 10 tabs on each browser window.