1. Keeping audio sync is not a problem, just a little time consuming as I have to load up two VirtualDub's, one with the source audio+video and the other with the destination video, then check every few thousand frames that the frames of the two VirtualDub's are aligned and add/remove frames from the source as necessary then save the wav which will then fit perfectly to the destination video.
A process I've done before for putting audio from VHS to the video of a DVD (the '89 film The Wizard) and the CGI cartoon ReBoot (I have 9 high quality Russian DVDs that are dubbed in Russian so synched the video to the VHS audio I have)

2. DVDShrink can't deal with XviD avis, I knew the first encode wouldn't be on-the-mark as I had to give a rough guess at what quality setting to encode it to, the next encode should be very close to the mark but I can't decide what audio to put with the XviD (AC3,PCM or the standard mp3)

I did a 30 min PAL DVD test and it's looking amazing, you start noticing more of the details in the film such as Darth's helmet isn't very shiny when you first see him

but I can't do a full DVD yet until I free up more space or get a bigger harddrive, I could do with replacing the two 120gb's with 250gb's.

Aurebesh? I never was any good at languages, oh er I mean I translated it for us lesser mortals who only speak one language