Cool script - but here's the error I get when trying to reopen After Effects (CC) after trying the keyboard shortcut change
It looks like you have a funky character after the parenthesis. Make sure you are using a plain text editor to edit the file and copy and paste a shortcut from another line including the quotes and then change the shortcut to what you want. Also, remember that on mac you need to put the 1st item on ExecuteScriptMenuItem02. If you are still having trouble open a support ticket and send us your shortcut file and we will fix it for you here.
It is cross platform