Yes, you can set Repertoire > Layouts > [layout name] > Edit Details > Actions > Full-Screen Document Open to show the lyrics full-screen. Then set Settings > General Settings > External Display > Content to Doc +1, and put all your videos in the second position in the Documents list on the song edit pages, to show the video on the external screen. When the video ends, you will see either the last frame of the video or plain black -- I'd have to check to be sure.