How can I run Mac OSX graphical Emacs in daemon mode?

1. You've got this handled

2. Yes, you'll want to use emacsclient. To get a new frame, add the -c option. I have an alias to make it quicker and to tell emacsclient not to wait for emacs server to return:

   alias em='emacsclient -n'
   

3. emacsclient -nw
4. I'm not sure about this. I start Emacs once and always load new files either within emacs or using my em alias.

Update:

Check out this tip documenting how to use Platypus to create an app wrapper around emacsclient. You could then use "Open With..." to launch using your new app wrapper.

Yes, here is an pretty comprehensive explain about how to do this nicely. I tried several methods to get it working nicely, but no better than what they described here.

https://gist.github.com/304964

Cheers!

For 4. put this in your .emacs:

(setq ns-pop-up-frames nil)

The solution of creating a Mac .app (with Platypus) does not work because Mac won't open the same application twice.