I just wanted to mention that I have converted the incredible guide that started this post in to a (hopefully easier to read and use) wiki version:
http://wiki.project1999.com/EverQuest_in_Linux_Guide
Over time I'll try to also add the knowledge from the 23 pages in this thread, as well as the other Linux threads, and maybe I'll even find time to add some screenshots too. But at the same time, if you see any improvements at all that you can add to the wiki page PLEASE, PLEASE do so!