Is there an addon where it will stop all buff noises and attack noises but you can still here the bosses talking. I like listening to the bosses when they talk and i usually cant hear them when my gun if going of or other people are buffing or attacking.

No addon can do that, but if you create blank .mp3 files, named after your sound effects you want to mute, you can put it in your \Data folder. To learn which sounds you need to create blank .mp3s for, you will either have to Google or get the Blizzard Interface kit (free) and browse the files.

Yes, it is a pain, but it is what it is.

It has been done with gun shot addons that silence the sound of guns.