You are correct in that some shortcuts do require a click, and I suggest you file bug reports with Apple (I've filed a few). I believe that since Xcode 4 is quite new, they just haven't gotten this far yet. I, for one, would love a keyboard shortcut to jump to the definition of the symbol my insertion pointer is in; but I've gotten so used to cmd-clicking the symbol that at this point, I probably wouldn't use it.