Hi John,
Encore is not an Edit-Tool, it´s an authoring-tool.
the best way to go is to edit your video in premiere, export it as a single film and import the final (edited) film to encore for authoring.
if you´ll do one more step, you can encode your video to m2v and AC-3 for authoring, that´s what DVD-authors would normally do prior authoring. we never take a mov- or avi-file into authoring.
when you´re encoding your assets prior authoring, you have a much better control of it´s quality.
so the best way to go would be:
1. edit your film in premier
2. encode your assets with adobe media encoder
3. author your dvd/bd within encore
cheers
danny