I would recommend a more strict check than proposed; rather than "if
the directory-to-be-removed matches one of several hardcoded regex's",
I would prefer to see: "If it doesn't look like a manually added
user":
if ($usershome !~ ^$DHOME && $force!=true) {
// Warn, exit, whatever
}
Where DHOME is easily parsed from adduser.conf.
Justin