addendum...

 You have 28 buttons the list is too long to mention...you can get a free download to change the paper list that goes behind the windows from black numbers on white to white numbers on black background.
 
These buttons mimic the actions of the HUD on-screen. I wish these were lit, but as for now they are not...extra cost.
 
You don't loose anything, all four viewpoints are covered by four buttons
 
You pan & zoom using a two way & four way rocker switches...free-interior cam is the way to go.
 
The only time I use the keyboard is to lap the brakes & using the find object tool, or to Ctrl+Z for details on traincars or objects & take screenshots.
 
You can switch the onscreen interface on or off with RailDriver as well as screen labels at switches, etc.
 
You have seven AI Driver buttons to switch between trains.
 
Here is the 
Support Page for RailDriver, take a look at the several web pages of info from there.