I never said that it was simply a coincidence that those two episodes are larger than the others; in fact, I'm certain that they're larger because there's extra space on the disc. However, that doesn't necessarily mean that they don't also naturally require a higher bitrate to maintain the same quality level as the other episodes. The producers may have purposely placed those two episodes alone because they're more visually demanding.

As far as your consistency requirements go, they're not authoring the discs for your convenience in backing them up. They're trying to provide the consumer with the best quality possible by using up the available space, which is completely logical. Besides needing to compress the video yourself, there's no downside for the consumer for them to do this. Even if you end up compressing the video yourself, it would more or less be exactly the same as if they provided you with a lower bitrate video to begin with (assuming you use a quality encoder yourself).

DVD Rebuilder is very easy to use once everything is set up. The one-click option makes things very simple.