quick update...
I think I found one way to do this, but since I have over 1,500 movie clips in iPhoto I may hold off until I get some secondary opinions and hopefully alternate options...
I created an album in iPhoto called "Move to iMovie". Then, I have a smart album in iPhoto with criteria to capture all MOV and MP4 files. This gathers all movies together.
Now, I'm able to copy the movies from the smart album over to the standard album. From the standard album, I could copy all of the videos (or in sections) over to iMovie by dragging from app to app. Then, I could delete all (or in sections) of the movies files from within the album in iPhoto to the trash...realizing one cannot delete files from a smart album.
I think this process would work, but I'm hesitant to try and move too many movie files at once, so I think I'll plan to do this in batches. That is unless someone here has any other ideas?
Thanks!