[ale] preventing interruption of auto install

[lyric hartley]

I have to do a bunch of remote autoinstalls using yast2. I need to
make sure that the someone does not try to interrupt the install.
Currently, I have 
-disabled the abort button. 
-added noshell=1 to the boot options. (however, this does not limit
viewing the logging done to tty3 and 4)
-removed the reboot if crl-alt-del is pressed in inittab in the root image 
(however, it will still reboot from tty3 or 4...which leads me to believe my 
change is not doing anything)

my current remaining issues are that:
you can kill X with ctrl-alt-backspace and kill the installation
you can reboot with ctrl-alt-del on tty3 and 4 (I would prefer that these were 
not even accessible...I tried removing the other tty* 
from /etc/sysconfig/keyboard in the root image but it had no affect)

I am not sure what of this is being done by yast and what is actually
getting controlled by the files in the root image...it seems that when
I make changes to the files the don't have any affect

yes, you could still hit the power button, pull the plug, etc. but I
can't do anything about that...but I would like to do what I can...as
having to send someone on-site could be costly

Any advice would be great!
thanks a lot!