Is there any way to sync iMovie, and all iMovie events and imports, bewtween two Macs? I need to edit the same file on both my MacBook Pro, iMac, and Mac Pro.
One way would be to transfer a Project and it's associated Events to an external drive, and then use that to work with iMovie. That way you can work on a Project on any Mac.
When you plug in an external drive, it's icon will appear at the bottom of the Project Library and the Events Library. Drag and drop a Project onto the icon. You will then be asked if you want to transfer the associated Events as well. Answer yes in order to be able to work on the Project on another Mac.
As an alternative to that you could just copy your both of your iMovie Projects and iMovie Events folders, that are in your Movies Folder, to the external drive.
Either way, they will then appear under the external's icon in iMovie.