Projects don't lend themselves to complex editorial systems as you're finding out. Yes, they don't work well on a network, but they tend to "marry" the computer they're on.
You need to know that Audacity projects will not open across versions. Audacity 1.3 projects will not open in 1.2, although it's supposed to work the other direction. Best to keep to the same version if possible.
If you use a number of external or pre-recorded sound files in your show, it's extraordinarily dangerous to try to move the show from computer to computer. You have to not only move the files (sometimes a surprise), you have to move the directory structure, too.
http://kozco.com/tech/audacity/aup1.jpg
This is a very simple Project file as an example. Count down to about line 7 and see my directory listing. /Users/koz...etc. If my sound files aren't in that
exact directory listing, Audacity will not be able to find them.
When you edit, it's best to tell audacity to pull all sound into itself for editing rather than leave sound in a collection of external files. That's a preference. "Copy all sound...(Safer)."
And if we haven't told you yet, you should probably be in Audacity 1.3.12. Audacity 1.2 has stability problems on modern computers.
http://audacityteam.org/download/
Koz