Discussion on answer by Arwen Undómiel: How do I delete my account and all questions/answers on IPS, but keep it on all other SE sites?

Imported from a comment discussion on https://interpersonal.meta.stackexchange.com/questions/2889/how-do-i-delete-my-account-and-all-questions-answers-on-ips-but-keep-it-on-all/2890#2890