How about putting a track of Media Generator solid color "Black" on the track under your clips. If you are asking how to automatically separate each clip from the following one with a 2-second space I don't have the answer to that. But 14 clips is not much to handle manually.
You can easily insert a 2 sec gap between events if you have Vegasaur or the free Timeline Tools. However, the simplest thing for just 14 events is to first create a 2 sec black event (add solid black event using Media Generator and re-size it to 2 sec), copy, and then paste between events. You can use built-in keyboard shortcut to move to the next event (Ctrl-Alt-Right Arrow). The whole process could have been completed in less time than writing this post.