Disable use of MacVim keyboard shortcuts - keyboard-shortcuts

Question

Is there any way to disable keyboard shortcuts in MacVim? I mean the shortcuts like Cmd + s for example, I want to convince myself to use things like :w, but I can't do so if I can save the file using Cmd + s, you get me?
But I of course, still want to use the GUI, so is there any way to disable these, without stoping using the MacVim GUI?
Thanks for your help. BTW I made a Google search and wasn't able to find an answer.
EDIT:
Following #ChrisJohnsen's suggestion, I have already tried the following with no success:
if has('gui_running')
macmenu File.Save key=<nop>
macmenu File.Save\ As\.\.\. key=<nop>
endif
EDIT 2:
I moved the error I'm getting over to this other question: When I try to run vim in command line I get Python errors

Answer 1

There is no simple way to disable all of the pre-defined Mac-style keyboard shortcuts, but you can definitely change/disable any of them. The important command is :macmenu (see :help :macmenu); it lets you set the Mac-specific properties of any Vim menu item (mostly Mac-specific keyboard shortcuts and Mac-specific actions (e.g. open/save dialog boxes, window manipulations, etc.)).
macmenu File.Save key=<nop>
macmenu File.Save\ All key=<nop>
macmenu File.Save\ As\.\.\. key=<nop>
The thing is that :macmenu commands are only effective if they are in your .gvimrc file.
If you do :e $VIMRUNTIME/menu.vim and search for macm, you will find the list of pre-defined shortcuts and actions. Copy the desired lines to you .gvimrc and replace key=<whatever> with key=<nop>. You can also wrap them in if has("gui_macvim") / endif if you need your .gvimrc to work on multiple platforms.

Answer 2

MacVim has only one "advantage" over plain Vim: it supports native Mac OS X shortcuts. If you don't want those shortcuts you might as well simply use plain Vim.
FWIW, when I switched from TextMate I, too, found after a while that these native shortcuts were an obstacle on my way to learning Vim. My solution was to focus my efforts on plain Vim. After a week in the terminal you should be able to completely disregard those shortcuts.
I'd advise you to take a little pause and think about doing things in a more appropriate order:
In the terminal, do $ vimtutor as many times as needed.
In the terminal again, use $ vim for simple tasks first then more complex tasks. There's a predictable productivity hit at the beginning but it will last only a few days/weeks.
Once you have reached your previous level of productivity, you can start to fly Vim full-time. At that point, using MacVim or GVim or plain $ vim should make no difference whatsoever.
Bonus points for not relying too much on plugins, other people's vimrcs or "distributions" like janus or spf13…