That would be great N3M3S1S.. If you're going the the Final version just add 1 global dialog for all kind of blacklist. As your explanation about the host that being changed to proxy means the same with nick also. They can change it whatever they want. Here is the example of my current black list dialog..
http://img52.imageshack.us/i/bldialog.png/
As you can see there i can put any format of blacklist that i want. But its not as good as yours. It has no power of scanning etc. Good luck for the best final version :)

Sorry for being talkative on your script.. :)