I'm sorry noone else got in on this topic because I thought it would be a fairly basic yet common procedure.

In the end I had to use a variety of tools to combat both normallyt encoded DVD discs and also a DVDRAM with a .VRO or something. I also found I couldn't edit the sound which I needed for some of them if it was in ac3, and dvdauthor didn't accept wav's for a project.
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The general lineup though was :

-Combine vob's into 1 with joinvobfiletool

-Demux vob or other container (in case of the DVDRAM disc) with either vobrator, vobedit, or TMPGenc (didn't want to rely on that since it's not freeware)

-Convert ac3's to wav with AC3tool

-Edit any audio stuff with audacity

-Convert wav to AC3 with ffmpeggui

-Load demuxed m2v and ac3 into cuttermaran and make any cuts needed and add chapters and take chapter screenshots if needed and menu screenshot if needed

-Load the cut/edited output m2v & ac3 & chapterlist into guifordvdauthor & create menus and chapterlists etc the choose createdvd
(If you're not interested in a dvd menu then IFOedit can be used instead of guifordvdauthor)

-Use imgburn to make an iso from the directory made with dvdauthor and then burn ay dvd's from that iso
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There - no video reencoding whatsoever. But I did work all through the night on them and skip sleep just to get them finihsed before they were needed /yawn

All the above software is freeware with the exception of TMPGenc which was on trial. Hopefully the other demuxers always provided a way to get what I want without TMPGenc though for if I need to do the same thing again.

Sidenotes I would say are editing in cuttermaran can be hard because it doesn't give you any sound, so you're left to make visual clues or line the shot up with what you view in a mediaplayer to hear where the sound is - and if you're trying to edit the sound to go with an edited video - good luck - you'll have to do that seperately then put it back in I guess. I had to edit the video then edit the sound seperately in audacity for a muscially accompanied dvd.

Other tools that helped along the way were things like VLC mediaplayer for file testing/viewing/listening and even on one occasin converting (before I found AC3tool which is more reliable for ac3->wav) and I tested the dvds by dropping video_ts.ifo onto WMP and also tested the burnt dvd's on an xbox 360 to make sure all my buttons worked etc.