chroot and NFS

trying to minimize the disc space in a chrooted environment, I found the only practical way in mounting the "big" trees /bin , /lib , /usr as NFS, exported from localhost. In doing so I have control about what my virtual server users can do and the security task is done well. So far everything works fine, BUT: there is a limit of 128 mounts (I need 300) My questions are: 1. how can I get 300 mounts from localhost on localhost? 2. is there another way to support "virtual" directories in an chrooted environment from "outer space (localhost)" I assume, localhost NFS is secure!? Thx 4 all help, Bernhard