An obscure one, to be sure. If I include a video and use jAlbum editing to "trim" the beginning and/or end of it, the videoDuration variable retains the original duration of the video, not its trimmed duration.

I hear ya', but under what circumstances would knowing the duration of the original video be germane? By analogy, if the original video is 1920x1080, but you tell jAlbum to scale it to 720p, the video width and height are reported as 1280x720. Same logic - there's no way to get to the original, so its stats are irrelevant. All that matters are the characteristics of the video that's in the album.