Xterminals, NFS, and tftp: need advice

["Susan G. Kleinmann" <sgk@sgk.tiac.net>]

I'm trying to set up a computer running Linux as a host to an NCD Xterminal.
As far as I can tell, the NCD uses tftp to fetch its server program from
its host.  Once that's done, the NCD can be set up to use either 
tftp or NFS thereafter, to get its config files, fonts, etc.
(It also writes logs via either NFS or tftp, but I'll be I can turn off
log-writing.)

NCD recommends using NFS rather than tftp for all file fetching and putting
after its Xserver has been downloaded.  Further, they recommend that if one
must use tftp, that he use what they call "secure tftp" (oxymoron?), by 
which they mean a tftp that can do a chroot, in the way that ftp handles 
anonymous users.  I am reluctant to use NFS because I suspect that it will
place a more significant burden on the host computer than tftp.

Here are my questions:
1) Is there a reason why the version of tftp that does chroot'ing isn't
included in the Linux distribution?
2) Is the fact that tftp is run as user nobody enough security?  That is,
would chroot capability not provide much more security?
3) Is there something else I can do to make the tftp that is distributed 
with Debian more secure?
4) Am I right in suspecting that NFS will burden the host substantially more
than tftp?

Thanks in advance for any advice,
Susan Kleinmann
sgk@sgk.tiac.net