This is hardly ideal, but ns-win.el contains the NS port customizations. Here's the relevant bit (starts at line 103):
;; Here are some Nextstep-like bindings for command key sequences.
(define-key global-map [?\s-,] 'customize)
(define-key global-map [?\s-'] 'next-multiframe-window)
(define-key global-map [?\s-`] 'other-frame)
(define-key global-map [?\s-~] 'ns-prev-frame)
(define-key global-map [?\s--] 'center-line)
(define-key global-map [?\s-:] 'ispell)
(define-key global-map [?\s-?] 'info)
(define-key global-map [?\s-^] 'kill-some-buffers)
(define-key global-map [?\s-&] 'kill-this-buffer)
(define-key global-map [?\s-C] 'ns-popup-color-panel)
(define-key global-map [?\s-D] 'dired)
(define-key global-map [?\s-E] 'edit-abbrevs)
(define-key global-map [?\s-L] 'shell-command)
(define-key global-map [?\s-M] 'manual-entry)
(define-key global-map [?\s-S] 'ns-write-file-using-panel)
(define-key global-map [?\s-a] 'mark-whole-buffer)
(define-key global-map [?\s-c] 'ns-copy-including-secondary)
(define-key global-map [?\s-d] 'isearch-repeat-backward)
(define-key global-map [?\s-e] 'isearch-yank-kill)
(define-key global-map [?\s-f] 'isearch-forward)
(define-key global-map [?\s-g] 'isearch-repeat-forward)
(define-key global-map [?\s-h] 'ns-do-hide-emacs)
(define-key global-map [?\s-H] 'ns-do-hide-others)
(define-key global-map [?\s-j] 'exchange-point-and-mark)
(define-key global-map [?\s-k] 'kill-this-buffer)
(define-key global-map [?\s-l] 'goto-line)
(define-key global-map [?\s-m] 'iconify-frame)
(define-key global-map [?\s-n] 'make-frame)
(define-key global-map [?\s-o] 'ns-open-file-using-panel)
(define-key global-map [?\s-p] 'ns-print-buffer)
(define-key global-map [?\s-q] 'save-buffers-kill-emacs)
(define-key global-map [?\s-s] 'save-buffer)
(define-key global-map [?\s-t] 'ns-popup-font-panel)
(define-key global-map [?\s-u] 'revert-buffer)
(define-key global-map [?\s-v] 'yank)
(define-key global-map [?\s-w] 'delete-frame)
(define-key global-map [?\s-x] 'kill-region)
(define-key global-map [?\s-y] 'ns-paste-secondary)
(define-key global-map [?\s-z] 'undo)
(define-key global-map [?\s-|] 'shell-command-on-region)
(define-key global-map [s-kp-bar] 'shell-command-on-region)
;; (as in Terminal.app)
(define-key global-map [s-right] 'ns-next-frame)
(define-key global-map [s-left] 'ns-prev-frame)
(define-key global-map [home] 'beginning-of-buffer)
(define-key global-map [end] 'end-of-buffer)
(define-key global-map [kp-home] 'beginning-of-buffer)
(define-key global-map [kp-end] 'end-of-buffer)
(define-key global-map [kp-prior] 'scroll-down-command)
(define-key global-map [kp-next] 'scroll-up-command)
;; Allow shift-clicks to work similarly to under Nextstep.
(define-key global-map [S-mouse-1] 'mouse-save-then-kill)
(global-unset-key [S-down-mouse-1])
There are a few NS specific ones in there, but I imagine you should be
able to find the Mac port equivalents, if they exist.
You won't be able to just eval the file, though, as it contains a lot of very specific NS stuff that would probably break on the Mac port.
C-h k
and then pressing whatever keyboard shortcut you want -- that will let you see what keys are being registered? Then just bind those keys to things like copy (ns-copy-including-secondary) and paste (yank), or whatever else you want. In other words, don't worry about rewiring and remapping stuff. If you don't like a keyboard shortcut, then disable it or redefine it -- if you need one, create one.cua-mode
is activated. It sounds like that's what you're actually after.