Looks good, but when I load the map it only starts after about 30 seconds or so, and at the end, the vid screen goes black before it restarts.
Are you running vanilla Doom 3 or dhewm3 or Sikkmod? Do you have an ancient PC? If so, that could explain the delay (or maybe your level is huge?).
The only way you can solve this is by using onTrigger in the gui script, and having a trigger brush around player pointing to relay trigger, which in turn points to any monitor with gui video on the level (at least the ones you want to be playing videos). So when you actually spawn and the game is playable, as soon as you move, it will kick off the playback.
Even with that you might still have black screen (which really is a background of that "monitor") between plays. The only way to solve it is by having an image of the first frame of the video as a background. Then when video is done playing, you'll see first frame of it and then it will play again. Should be pretty seamless.
Worth noting that RoQ videos were only meant to be played in the full screen GUIs such as PDA and intro screens.