bootloaders

I just installed the Grub bootloader that came with RH 7.3
and because I had some problems with Red Hat and X-
windows so I played around with the command line fea-
ture.

Now, I thought it was cool that I could use cat(equivalent
to type in DOS) to look through my RH config-files to see
what could be amiss. So, I was wondering if there is a
boot loader that could also edit files or do basic dir/ls and
if there isn't, how hard would that be to implement and
risks, if any?

Also from the security viewpoint, can one make one's
partitions unreadable or hidden to programs like this
or to other OS that could read my HDD?

SuSE has a lilo.conf editor in yast.

and I even believe KDE has it in it's controll center now..

you COULD use that..

but most people think stepping from grub to lilo is a step down ;)