I don't play with sound, so I can't help you there.
You need to actually have the Velious UI downloaded to use it. The default directory is C:\Program Files\Sony\EverQuest\uifiles. Inside this you need to place the Velious UI found here:
http://www.project1999.org/files/veliousuiv3.zip. You should then have a directory called C:\Program Files\Sony\EverQuest\uifiles\Velious. Obviously make alterations if your EverQuest is installed somewhere else. Once this is complete use /load Velious in game.
Only Titanium can be used because the entire server is developed around it. No other version of EverQuest is supported. If you're wondering why... there's a classic EverQuest project that's been in development long before Project 1999 and is still in development based on using the original Trilogy files. This project will probably be in development forever.
The Paineel and Kelethin lifts are a bit buggy and require 3-4 clicks to operate. Can't be fixed as of now I assume, since the devs have been aware of this forever.
The boat is a different model because during a DX update the original boat model lost collision detection. The solution was to use a boat that you could actually stand on, even though it's not the same classic boat model.
The boat routes themselves are wrong as well, I've tried to get devs to change this but to no avail.
For loading, death, and combat music either delete or move the following files outside of your EverQuest directory:
eqtheme.mp3
combattheme1.mp3
combattheme2.mp3
deaththeme.mp3