A particularly self-starting member of the Archicad community, Karl Ottenstein, has developed an add-on called QuickDisplay, which allows us to assign keyboard shortcuts to various display options. The commands are toggles, which means you can strike a key turn the Section Depth (e.g.) on, and then strike the same key to turn them off. He has generously allowed this add-on to be used free of charge. Here is the Archicad Talk topic where mad, righteous praise is heaped upon him.
Here is Karl's page with full instructions for the add-on. I will summarize the high points.
Get the file from 3 Resources : Add-Ons. Place it in your local Applications : Graphisoft : Archicad 9 : Add-Ons. Launch or relaunch Archicad.
Your Display menu should now have a QuickDisplay submenu at the end. Here you will see commands for toggling various display options.
QuickDisplay Submenu
Naturally, and I hope obviously, you don't go to this menu to activate the commands. That wouldn't be much of a shortcut would it. The commands have to be on a menu in order to have shortcuts assigned to them.
As you can see, I only have shortcuts assigned to two of the commands, Section Depth and Line Weights, on F4 and F5 respectively. I toggle the others much less and I don't need a shortcut for them. You can do whatever you want.
I have updated the RND Keyboard scheme with these two shortcuts. You can import the updated scheme at Options -> Work Environment. The scheme is located at 3 Resources : Work Environment : RND Profile : Shortcuts.
For information on assigning shortcuts, see the Archicad Reference Guide, page 153, or ask for help.