Been awhile since I've used my Systems Analyst kung-fu..
In addition to most of what you have tried I;
*turned models on and off
*turned cashing on and off, thinking maybe client was getting confused on where it was loading files from...
We can log onto SoD fine and even get to our character select screen without issues. but entering world, or zoning is a problem. I wish we would have a night of no crashes. We just accept that we are going to have to restart the client over and over each time we zone, or try entering world. Once we are in the zone and fighting, we have no problems whatsoever, its just getting all of our toons traveling through multiple zones to fight or quest..
I'm also using the same files copied and pasted across an XP, Vista and Win8 laptop. Maybe thats the issue, something is corrupted in my files. These files were working 6 or 8 months ago, I'm not positive how long ago. But I believe people said they were still having crashing problems after a fresh install too..
I noticed the other day that most often in cities I will crash, but when I got away from them out where I was the only toon in the zone I had a higher success rate, but hard to test when I really cannot tell how many people if any were in the zone when I do crash..
I have not tried a fresh install of the EQ files, I'd just have to look up the expansions, since I have the original expansion disks, not the combined edition and would try to install in order. Need to check too if I need update from Sony servers or just install the base files and then update from SoD..
Regards,
Rayzer