I would go to the Slave's keybindings, and find an empty one without a bind.
Click on that bind, and then do Mouse Button 4.
Whatever mouse 4 was bound to, it won't be bound there any more.
Click on the bind again, and then disable it.

As for the sound, I'm guessing only the active window is broadcasting sound.
Not sure on a fix for this.

Jamba has follow options.
Normal follow can break as easily as any other type.
But you can also "strobe" follow, which is the same as typing /follow every second.
So even if it breaks, it will start up again very quickly.