I absolutely hate the volume warning, but there is a way to disable it on the at&t version if you are rooted, and there is probably a similar way for the other versions as well. If you are on at&T, there is a a thread on xda for an app called NottachXposed which requires the Xposed Framework to be able to work, both are extremely simple to install. And it gives you a ton of customization options, most important for me was letting me get rid of the green icons in the notification bar. Here is a link to it http://forum.xda-developers.com/showthread.php?t=2285074
, again this is for at&t only, but just assuming there will be something similar for the other versions.