Nina - Thanks in advance for your help. Having the help of someone with a good eye is always a good thing. :)
Martin - Cool; let's do that then. :) You want to do the initial setup? Or should I?
As for the LUA - it's really not that bad. I had found an old .NET v1.1 LUA parser that would parse the file and allow you to walk the structure as tables and variables. I've been using that for reading and generating LUA files for my guild roster module. I had also written a thick-client Windows app that could parse the GEM LUA into objects that could be used in a data grid (or wherever, really) - and I think this is just an extension of that...writing from a web UI or web service. On the file side, you can set a file watcher in .NET that causes an event to fire whenever the file is updated -- this would mean that a thick-client 'monitoring service' would run on the client and be notified when the file changes, then call the web service to synch the changes. The other option is the user can launch the 'synch app'.
The only real issue with this, from my digging about on the GEM site, is that GEM only flushes their data into the LUA file when the user logs out...I assume this is Blizzard's way of enforcing their ToS of no outside interaction apps in the game or interception of game data.
But those are my thoughts - does that help?...I know Logan had some of his own, and I think he's been playing with the GEM side over the past few weeks...and I'll leave it to him to detail where he's taken it.
Also, if you are interested in the LUA Interface assembly - let me know and I can send you a link to it...or link it here.