So first place, would it be possible to offer some more 'numpad' keys for the main menu toggle besides the numbers? Like INS, /, etc.?
I'm sorry, but that menu is not made by us, it's a standard Simconnect menu, which has very rigid restrictions: no more than 10 choices, and they are always mapped to the standard keyboard from 0 to 9.
The only alternative is to use a programmable keypad, such as the Logitech G13http://www.logitech.com/keyboards/keyboard/devices/5123
So you could map the layout as you want, to generate keystrokes from 0 to 9, and perhaps CTRL+F12 too.