Abut renaming pibbur, this is what I've done a couple of times
1. Inactivated myself by entering an invalid mailadress in my user profile. Then the account becomes unavailable, and is marked by "guest" in all posts. Just look at the first post by "pibbur" in the Things you don't need to know thread. You can't do anything with him, like sending a PM. He's gone, but his messages remain.
2. Then, when I regretted my actions as I always do, I had two choices. Either asking Myrthos to revive me, which has happened once or twice, thanks to Myrthos. Or, more often, creating a new account, with a new pibbur-like account name, as the old names were taken. Thus we also have "pibbur 42", "pibbur 0x2a" and a couple of other incarnations I don't remember.
Why do I do things like that? It was never because I was unhappy with the watch, but because I was unhappy. Self destructive. And a bit stupid.
pibbur who who has been pibbur who for who knows how long. But much longer than any other pibbur.