That config is not for terminal Emacs. It's only for when you are running a native cocoa Emacs (like http://emacsformacosx.com). For terminal I always enable option as the meta key and use the OS Character viewer for the rare times I need to type a unicode character into the terminal.
Having option as meta is useful outside of Emacs, as "bash" (and other shells) use Emacs keys by default (M-d, M-f and M-b are all essential for me when I'm using bash).
I wish the OS would let me use the Fn key for doing fancy unicode characters (maybe Fn+option or something)—that way I could have good unicode input and my precious meta key.
I use https://github.com/andymcd/cmd-key-happy which swaps option and command, and which lets you whitelist keys (iirc Cmd-N is among the defaults) to be exempt from that swapping.
Iterm2 will let you swap option and command. I also cheat and use Keyboard Maestro to UN-swap Cmd-Tab and Cmd-` so that application switching and window switching still works.