if you want something changed (like a ship SKIN or sound files, or weapon/engine effects), you need to PM the admins with your intentions.
In example, I used to do ship skinning. It only changed what a ship looked like. I pmed the admins with my intentions of changing ship skins, I thouroughly explained how I'd do it, and provided a sample of how it'd work out.
After that, its up to the admins to say yay or nay to it.
Changing sounds shouldnt mess with the installation UNLESS you modify the INIs which is always a nono. What you do is you just replace the default music with your music and rename it to match.
that also includes format.
but like I said, if you're changing ANYTHING to the mod itself, whether it be skins or music, you FIRST PM the Admins with your intentions.