"then it goes to some kind of distribution system in a room next to the stage and from there to the board. The Hotel had an AV company install the whole thing and the PA is used for the house sound, DJ's and band. The Board is run through their whole convoluted system through a bunch of BSS software, an ethernet routing system etc."
Here is where your problem is in your description above. You can run CAT5 300ft with no issues.
Get a CAT5 cable and run straight from the x32 to the first snake and the other snake is daisy chained to that.
If you can get your hands on a Fluke network/cable tester then you could troubleshoot this whole issue a lot easier.
You can hook the Fluke tester up and shoot a tone through the whole system or cables and find the issue.
The first thing I would do is bypass EVERYTHING and go straight from the x32 to the snakes.
Fluke Linkrunner
http://www.stanleysupplyservices.com/fluke-networks-linkrunner-at-network-auto-tester/g/23764