Be honest Tom...You're trying to make the audio section work because...YOU HAVE NO EYES (dum dum DUMMMM!!!!)
Ok those who don't get the joke obviously don't know Mr.Fulp's acting career.
Anyway its clear that he is feeling concerned about the uploading of these musics distributed because they were done by other people but I have an idea:
What if you wanted me to split this answer into your 2 solutions so that you get a decent reply.
No.1: Keep the system up and let it flow as it is: Now you realise its going to still have people doing this and that's never going away, no matter how many heeded calls from you or anyone else however suggesting that limitation people do wonder what next: Sound effects? That's...
No.2: Scrap the current idea and make the zip files full of sounds.
Now that's a good idea but its not without any arguements of how the others arn't getting a say. So the options seem limited considering e-mails to suggest music will fail as you're too busy a man to bother over those e-mails supporting the overwhelming amount you must get anyway.
Let's take this: I, as a flash artist, could say ''I won't do this, in fact I could easily snap up a music generator swap it's format to wav. then put it into newgrounds'', but that's only me. Its a tough question to answer but what if you got mods that take up time, just like you, to share ideas that's not already done and can prototype these musics. That way it stops all the annoying people submitting the musics we don't want around however this still doesn't stop mass e-mails to a larger picture. However the good news over the bad news is that it can work both ways.
2. Logically varied.
That's my idea and I take much tired thinking to it. Well I've got to go soon otherwise I'll smash my head on the keyboard and submit a bunch of spam at the end.
Good luck in making choice but I think the people want this to stay: I'm sure newgrounds audio portal is meant to help flash artists: Getting rid of the concept will halt their help and make it less of a effort for the others. Its the job of the people, not just you, to make good sound in any flash and that cornerstone starts it.
I say keep it but don't be alerted if I am happy if it goes but I say keep it.