When I lower the effect volume it stays the same after I change map, when I change the BGM volume however it returns to its default state as soon as I do. It's kinda loud and I can't lower it more in Windows volume control.
You have to run opensetup at least once with administrative privileges. Opensetup.exe, thor patcher.exe and MarvelousRO.exe should all have their permissions set to administrative to prevent issues in Windows Vista and onwards.
Try setting opensetup.exe to store client preferences in your windows registry instead of lua files. Our server doesn't make use of .lua files, it uses .lub format files which cannot be directly modified if they are encrypted. I may try changing the .lua extension to .lub to see if that fixes the issue, but if I'm not mistaken I tried something similar before with the result being that the client (or opensetup) would just create a new lua file.