Luckily you can not fire rockets in the game, so you don't need the button!!!
Can't you revert everything back to "default" ?? This of course will erase all commands that you assigned, bringing it back to the original factory default. I did save my assignments in an INI file. This is a new option that might come in handy. The INI file file that you save with the keycommands are stored in the my documents\1C softclub\Il-2 cliffs of dover directory I think. A backup file of key assignments is saved in the confUser.ini in the same directory (and the steam il-2 directory)