Symlinks in /var/www not changed when a site is moved
2/ links in /var/www if ISPC3 make symlink for first time to /var/clients/clientx/ in /var/www and via ISPC3 you will change location to /var/clients/clientx/anotherweb, ISPC3 dont delete/rewrite link in /var/www. Its a problem, because /etc/apache2/sites-avaiable/site.cfg contain old location and not contents.