I think the top bar is one of the really good design features of UT: it breaks system settings into logical groups, and they're literally one slide of a finger away.
It also goes beyond just being a settings feature, with the calendar, and the email/matrix notification functions. Personally I'd like to see that extended more, but I know I'm in a minority on that one.
Making the top bar itself customizable is an interesting idea though: I never use the Files or Language settings, for example, but I know that other people do. And they're always available under the settings icon, of course, for those odd times when they are needed.
"Making the top bar itself customizable is an interesting idea though"
+1 to that.