Q Slide can be disabled. If you are on AT&T, you can't get rid of the volume/brightness sliders unless you root.
Baffling to me. Q Slide is definitely the biggest offender in taking up realestate, but I don't need two sliders there constantly either. They're more manageable on their own however.
Considering how much of the rest of the OS is customisable it's strange that you can't remove those.