Reply to Collection syncing among computers and backup Nirvana

So I've read just about every thread I can find on syncing and backups, etc - Played with a few schemes to accomplish a few goals as simply and gracefully as can be managed, but need some advice.

The goal: Create a method of keeping one prep computer (desktop hackintosh w/ separate music drive) one playout computer (MBPro w External HD) and one backup (MB air w/ external HD) all in sync with regard to Traktor. That means pre-gig, everything pushes from the Desktop to the Lappys, then post-gig, everything pushes from the Playout lappy back to the Desk and backup rig.

It SEEMS like backing up and distributing the Traktor root and music libraries are the way to go - The problem, is that the music - as Traktor sees it - is always "missing" after an update from another computer. This, of course makes sense: Move the collection to a new computer, and suddenly the music is no longer where it used to be. (I sure wish there was a baked-in way to point Traktor at root music folder, and as long as the contents were the same, have it "just work.")

This is somewhat addressed in many threads that discuss "moving" a collection either for better housekeeping or when swapping a drive in an emergency, but doing a consistency check and then re-locating the library each time doesn't seem feasible for a library that's over 100 gigs. (I also believe it is way too cumbersome to be a recovery method for a pre or (god forbid) mid-gig crash, so my plan-b is another laptop.) Is there a way around all this?

One possibility I've considered is using external drives and giving them all identical names. One reason I keep trying to believe beyond this is that I'd like to find a solution that also allows for multiple users to gig off the same laptop after a quick drive change. Not really feasible to have everyone name their drives identically.

For some of the same reasons, iTunes is kind of a non-starter for me, and because I simply don't trust Apple not to suddenly and arbitrarily break iTunes for our purposes.

I'd love to hear if anyone's been down this road, and how they worked it out. Thanks in advance!