Lightroom :: How To Use Chronosync To Synchronize Catalogs On The Macs

I have a project that for security reasons requires that media NOT be stored in a cloud.  I'm trying to build a system that keeps a Lightroom catalog and the pictures synced between two or more Macs.
 
My current plan is to use Chronosync to synchronize catalogs on the Macs, and have all the media on a network server so that each Mac uses the same path to reference the original.  But I can see two ways of this method breaking:

If both catalogs get modified simultaneously, or at least before a syn. [kind of just how it is, but could be managed with discipline]If some media is shot while the laptop is in the field, then I can sync the catalog and media when we get back, but the Lightroom catalog will still be pointing at the media on the local storage on the laptop.   That second case worries me.   Since Lightroom is nondestructive that avoids the truly dangerous case of someone on the laptop continuing to work on the wrong (local) copies of the pictures, not realizing that they're not updating the shared copies, but still, it seems that I should actually MOVE, not mirror the laptop data to the server when we get back into the network so that we are forced to locate the new media next time we try to access it from either computer.
 
Actually -- IS Lightroom truly nondestructive?  Does metadata get changed in the DNG, or is all metadata stored in the catalog?  Is there an option I'm going to need to set?
 
Is there a better way to handle this? 
 
What is the best way to make relinking files go smoother?  Maintain the folder structure relative to... what?