Edit doesn't work right from cmd.exe... it'll crash on exit when it tries to load command.com...

...Assuming you are the Administrator, you shouldn't have to worry about boot.ini's security.  In my expereince, the Plan9 option for setting up the boot menu will set things up right in principle, but it won't work when you select the "Plan 9" option. (that could be because my P9 install was on a different HD) I've heard it said somewhere that instead of having some sort of pointer (I forget what exactly... XP system not present currently), you can copy the boot sector and imbed it directly into the Plan9 section in boot.ini.  Hope that helps...

-Ben