The Auto width setting is used by AutoGK when you specify a precise file size. The program will calculate the best quality and will choose the resolution automatically.
If you want an exact resolution, you can specify it manually.
I suggest to use AC3, i.e. leave the audio untouched to get the best quality.
If you want the best quality, and file size is not important, then leave each file untouched, i.e. as VOB files. You can create a video DVD containing each episode with any authoring software. You can find some here
Sorry, I'm not able to answer this question
My guess is that autogk is saying that is pointless to convert a 1800MB VOB file into a 1800 MB avi file. If you want to keep the same file size, then why do this conversion? The original file will anyway have a better quality.
In fact, "compressing" a 1800MB VOB file into a 1800MB avi file is like to convert a mp3 file into an OGG file: being both compressed formats, the conversion will inevitably cause a quality loss.
My suggestion is to use a DVD authoring software to make a video DVD. In this way you'll have no quality loss