Deleting his pages will just leave redlinks everywhere, inviting people to recreate them.  I like the blocking, blanking and protecting idea.  You're right, there is no way to remove all traces, especially when he keeps showing up and signing his rants with his name.  Nor is that our problem, really.  We can do what we can, but if he really didn't want his name showing up everywhere, he probably shouldn't have used his full name as his user name.