redefining xah command mode keys

my-command-mode.el

(defun my-command-mode ()
  (define-key xah-fly-key-map (kbd "p") nil)
;;  (define-key xah-fly-key-map ...)
;;  ...
  ) 

(add-hook 'xah-fly-command-mode-activate-hook 'my-command-mode)

this way you can just use normal define key and qwerty references

Ahh Excellent. Maybe I'll give it a try now.

What is the form of that argument that I am setting to nil?

from the documentation on define-key:

DEF is anything that can be a key’s definition:
 nil (means key is undefined in this keymap),
 a command (a Lisp function suitable for interactive calling),
 a string (treated as a keyboard macro),
 a keymap (to define a prefix key),
 a symbol (when the key is looked up, the symbol will stand for its
    function definition, which should at that time be one of the above,
    or another symbol whose function definition is used, etc.),
 a cons (STRING . DEFN), meaning that DEFN is the definition
    (DEFN should be a valid definition in its own right),
 or a cons (MAP . CHAR), meaning use definition of CHAR in keymap MAP,
 or an extended menu item definition.
 (See info node ‘(elisp)Extended Menu Items’.)

It seems like what I want is to define a command that doesn't do anything.