Setting up Gordian Knot

I’m a bit confused about the audio settings in Gordian Knot. It seems there are two tabs where I have to select audio transcoding, in the Bitrate tab (here and here) and in the audio tab that pops-up after pressing save&encode (here) .

The later includes some extra options like Vorbis ogg encoding and APS encoding. What happens if I use different settings for audio under each tab? (eg. MP3 CBR 128 in the bitrate tab and VBR 160 in the other one).

And what happens if I check size instead of bitrate here?

Also, how do I rip a DVD without including the subtitles or at least by making them optional?

Finally, if I have an interlaced movie do I check kernel deinterlace or field deinterlace in the encoding options?