Did you fix "DSETUP.dll" specifically, and have you seen
https://wiki.project1999.com/EverQuest_in_Linux_Guide?
That video guide you linked starts out by claiming that you must have a VPN, which is nonsense, so I'm skeptical of its advice. This wiki page also has conflicting advice, but at least it's honest about it and admits as much, and it's got lots ideas. I'd also recommend searching the technical forums, as we've had several (long) threads about Linux.
Oh, also if you have a friend with Windows or another Windows computer, you can try installing/patching everything on Windows, and then just copy the folder over to Linux. That worked well for me (ages ago).