On a Mac, if you've saved a custom keyboard shortcut set in FW, it resides in your user library application support folder, for example:
user/Library/Application Support/Adobe/Fireworks CS6/en
The preferences for Fireworks are also located in your user library:
user/Library/Preferences/Adobe Fireworks CS6
This link may also be helpful: http://help.adobe.com/en_US/fireworks/cs/using/WS4c25cfbb1410b0021e63e 3d1152b00db4b-7ffc.html
