Is there a specific reason you want to script in C#?
Well one reason is being familiar with c# is one reason, the other one is the lack of reasonable IDE to work with. I'm not afraid of trying a new language, but not having a good IDE can be a really big pain. Is there a reasonable IDE to work with?
.. However, personally I can't stand the freakin' thing! So I make do without debugging (which, at times, becomes visible in my scripting) and use plain text editors -- my editors of choice are Textpad (Windows) and TextWrangler.
It does mean I cannot use the built-in Help, so I made my own version (using Adobe's data, of course): http://www.jongware.com/idjshelp.html
I agree with Jongware.
I find I code fastest in BBEdit. I only go to the ESTK if I need to step through a script. This is not usually the case.
For simple debugging, I just put in some alerts to give me an indication of what's going on...
Polymorphic. Yeah, def'n'tly, that was it: they are polymorphic.