The stability issue on Luclin, to me, has all the hallmarks of a hardware problem. It certainly doesn't feel like what I'd expect for excessive load, a DDoS or a database problem.
While I don't know much about how EQ servers are structured under the hood, I think something keeps going wrong with the component that lets groups of zones talk to each other. The other day, I was able to zone from CR to Blightfire just fine by walking across the zoneline, but when I tried to port to Blightfire from Blightfire, it failed, taking a long time to do so. If I'm right and groups of adjacent zones are running in the same process or thread but teleporting uses a different mechanism (as it probably would because it doesn't know up front where you might be porting to), then there's probably something wrong with however that communication mechanism works. Which, due to the way it keeps happening, smack of a hardware problem.
I'd think that DBG would get some kind of report about this, but it's entirely possible that, thanks to ancient weird artifacts, they wouldn't. Also, if the servers are running something really antiquated (like Windows NT 4.0, heaven forefend...) some of that data might not even be available easily.
Not that all this speculation matters much, but dash it all, I'm a sysadmin and someone who, when faced with a problem, wants to understand and fix it.