I’m curious about different possible workflows for using C# with Unity and the Mac Editor. Advantages?
As you’ve probably noticed, Unity has some pretty good workflows 
You can add your own wizards and menu-items in the editor, coded in C# (or JavaScript or Boo of course). There’s docs here:
http://unity3d.com/Documentation/ScriptReference/MenuItem.html
http://unity3d.com/Documentation/ScriptReference/ScriptableWizard.html
And some examples here:
I’m not sure if I fully understand your question though, so just continue asking until you know what you want to know
d.
i was referring to compilers for c# for using with unity on mac (since apple will probably never address its existence)
Unity includes a C# compiler. Basically you don’t even have to know about compiling c# code. You just put your script in the project folder and when you save it in your text editor, Unity detects it and automatically compiles the C# file.
If you have compile error, there is a nice console, where you can double click so it gets you right to the line that caused the error.