iTunes starts playing when disconnecting Bose Soundlink Mini
This (http://forums.macrumors.com/threads/how-to-stop-itunes-from-opening-with-bluetooth-speakers.1666895/) worked for me --

In Finder go to Applications and show package contents on iTunes.app. Inside the MacOS folder there is a unix script called iTunes, I renamed it iTunesclosed. Also renamed ituneshelper.app to ituneshelpdisabled.app

Remove the iTunesHelper.app from starting on login via System Preferences -> Users and Groups

Also kill the iTunesHelper process via Activity Monitor.

Edit: Note that you may have to do this every time iTunes is updated.