for 1:

http://www.zopelabs.com/cookbook/1021216110

for 2:

Thankfully, "Lucas Hofman":http://mail.zope.org/pipermail/zope-cmf/2001-September/009832.html provided a script to show how this can be fixed::

        def fixMembers (self):
            '''fixes ownership of the home areas'''
            import string
            users = self.acl_users
            Members = self.Members
            r=[]
            for i in Members.objectIds():
                try:
                    u = users.getUserById(i)
                    m = getattr (Members, i)
                except:
                    pass
                else:
                    if u is not None:
                        u = u.__of__(users)
                        m.changeOwnership(u,  recursive=1)
                        r.append(i + " changed")
                    else:
                        r.append(i + " not changed")
            return string.join (r,'\n')