The "Edit Privilege Set" dialog is the most important place where you can assign, revoke, restrict, etc. access privileges to users... ehm... "privilege sets". The number of clicks you need to perform to arrive at this dialog and the stupendous number of clicks you need to perform to attribute privileges are unpleasant (to say the least ).
There are no good views that show what access privileges you attributed to what privilege sets.
Another important and missing feature is "access privilege inheritance", which would allow you to declare one privilege set to be a modification of another one.
Instead of creating some kind of "inheritance", you could also solve this by combining and prioritizing access privileges. Imagine, you could assemble a "is allowed to edit x, y, z"-privilege and then a "is allowed to view a, b, c"-privilege. You could then combine these privileges into a privilege set. The order of the privileges would indicate which privilege takes prevalence in case of contradicting information. This would make the process a lot easier. Additionally, you could have a look at the collection of named privileges attributed to a privilege set and would get a quick overview of what a privilege set is allowed and not allowed to do.
There should also be a way to edit several privilege sets at once.
Last but not least, the look and feel of these dialogs should be catapulted into the 21st century. IMHO, they are really convoluted.