I figure this way i can uise the video once and only extra storage on the DVD itself will be audio and the 14mb intro titles for each use of the Peru main video.
The only problem is that it doesn't work that way. When you create a new timeline, there will be a vob on the actual DVD for that timeline. The video in 3 timelines will be 3 videos on disk. Someone correct me if I'm wrong.
Encore (any authoring program) takes demuxed streams (like the m2v you are referring to - a video only mpeg2 file - and if you don't give it demuxed streams the program creates them), and then it muxes the video and audio into the vobs that are put on disk.
The magic you are looking for is, as Richard notes, in the ability of a DVD to play different audio tracks for the same timeline.
I don't know if you can do what you want.
I would try something like the following.
One timeline per video. Add multiple audio tracks per timeline as needed. Use playlists to combine if you wish. Use navigation and "specify link" to get the right video with the right audio.
I did not realize till I saw your last post and then looked back at your original post, that you are also talking about putting different video (you can't just talk about a title and have it appear - it is video) with each timeline/video depending on what audio you are selecting. You might try adding a transition on the button that does that.