run /sbin/lilo after update IF you use LILO (don't know)
 

It says if you use lilo to run the above, I don't know if I use lilo. How can I find out and should I run it anyway?

Lilo is an alternative to Grub - Grub being the standard boot manager with Suse.

So , chances are. no - you don't need to run lilo.
But just for safty check in YAST just to be sure.

It is the very first thing in bootloader setup in system in yast. Mine says grub.

so does that mean if I ever want to switch will lilo work okay without running the above?

You should not run 'lilo'.

IF you use(d) lilo as a boot manager, when updating the lilo configuration files,
you run 'lilo' at the prompt to make the changes on the MBR.

Grub or Lilo is personal preference. If Grub is working well for you, there should
be no reason for you to change.

Hope that answers your quesiton.
-tw