Yes, you clock widget was made for portrait view and not landscape. With the jumping of the springboard, there is a free tweak called "SpringJumps" in cydia that will do this really well. What it does is create an icon with an arrow and a page number on it, and you can also name these icons as well. The "mimics driver" has two actions available in activator called "mimics connected" and "mimics disconnected", you can assign these to anything. The issue at the moment is that actions cannot be multiple, i.e. only one action per gesture at the moment.
In regards to shortcuts, there is "appLinks" but this only works with the appstore apps. What I can suggest is to have all you "InCar" apps on your last springboard page and use "SpringJumps" to get to that page when in "In Car" mode.