I was thinking of doing a video series, and I wanted to reuse certain clips that I trimmed down. Is there a way to save them so I don't have to reinsert the clip and trim it down again?
Render to a new file, preferably the same format as the original clip. If you have a bunch of stuff on the timeline you can double-click that event to select it. Then when you render go to advanced and check the box that says "render loop region only".
... or if you are doing the videos in different clips you might also copy and paste the trimmed events (or groups of-) from one project to another.
You can have several instances of VMS(P) open on your screen at the same time.