Installed kgrubeditor and played around a bit. Found that the start command in the menu launcher is incomplete. To fix, right click on the mintMenu icon to access "Edit Menu". Select "System Tools" Highlight "kgrubeditor", and select "Properties". The original command is
Just add "gksu" at the beginning so the command reads
gksu kcmshell4 kgrubeditor
This will make kgrubeditor visible in the Administration section of the mintMenu (if it was not there before) and allow you to launch and use kgrubeditor.
Once you get kgrub editor running, it is a much more extensive application than startup manager. It gives almost as much access to grub as the terminal and does it via a GUI window. Startup manager's only advantage is that it lets you choose the default OS via GUI without directly editing the boot menu.