The following should remove the staff banner if this is the method you want to take @
DRE
Code:
.userBanner.bannerStaff.wrapped span { display: none; }
.userBanner.bannerStaff { display: none !important; }
Edit: Probably best using the code below to hide it and eliminate using that !important i used above.
Code:
.userBanner.bannerStaff.wrapped span, .messageUserBlock .userBanner.bannerStaff { display: none; }