Well. Almost literally nothing is working out.
My friend couldn't put the videos together. After another failed attempt to export the whole thing or try combining them myself on a new file, I decided to give up and simply post the two parts on Vimeo and burn them onto the CD with everything else--except THAT isn't working out, either, as Vimeo (after forcing my hand and making me pay $10 dollars to bypass the "weekly 500 MB limit" thing) crashed twice trying to upload those two parts, and, they won't even play properly once burned onto the CD.
So. Going to try splitting up the project into fourths, see if that does anything...but for now, suffice it to say, there was a lot of gross sobbing tonight.