Rendering Codec
 

Why can I only change this in a new project in the project settings?
What is the best one? We are outputting to flash and mpeg-2 (DVD) with this project.
The Cinepack codec seems to take forever and all the other ones are alien to me. I have encoded with Xvid in the past but have no clue about this.

When I select export movie does it use the codec in project settings as well or do my new settings override?

Thanks