somewhere in the last 2.5 years I was able to add subdomain users. Or, to be more precise any my add-on domain works for any ftp user name. That is, joe@mydomain.com, joe@addon.com, and joe@subdomain.mydomain.com all resolve to the same joe. It's good to know - not to create joe@mydomain.com and joe@addon.com (since it ends up being the same account), but it's good enough for my purposes.
What I am trying to figure out is whether it's possible to let this joe to change his password? FTP server may have an extension ("site cpwd") but I don't think it's available here. Is there some other way that the user can change the password without giving it to me?
http://forums.cpanel.net/f34/does-anyone-knows-change-ftp-password-themselves-web-interface-130969.html seems to indicate that it's not possible (and in typical vendor fashion justifies absence of this feature by some weird security consideration) - but I was hoping that there is some miracle here.