Hi Kelly, Actually you can now place objects overtop of slide videos such as images and shapes. When you publish them they will appear on top of the video. You will need to place them on the same slide as the video, unlike overlay slides. Use the timeline to determine when these objects appear and disappear or you can have them appear for the entire duration of the slide.

Not with the interactive video functionality. This is possible if you capture with Video Demo. You can insert images and other non-interactive objects  on top of the video timeline in the editor. The frames for overlay slides have an interactive object which pauses the video while showing the overlay slide.

You can as always insert static object in the timeline, but that can lead to synch problems.