Well, technically won't "edit" your video in Architect. It's really more for DVD authoring -- although you can trim some off the beginning and end of your video, if necessary.

It's rrelatively easy to set the DVD so that it returns to the main menu (or wherever else you want) after every scene -- although to do it you'll likely have to treat every scene like it's own video. (Trimming each DVD Architect or, even easier, just outputting it as several short clips from Vegas instead of one long one.)

Directing where a DVD goes to after any media clip is as simple as setting its End Action (displayed as a link in the Project Overview panel).