Grub supports tab completition, so just type "root (" then <tab> - it'll tell you what it can see. Same applies to "setup", which I think you should be using instead of "install".
Quote from the grub manual re "install";
"This command is fairly complex, and you should not use this command unless you are familiar with GRUB. Use setup (see setup) instead."
As for booting a kernel off it, I'd guess you'd need an initrd/initram. Haven't done it, so hopeffully someone else can tell you for sure.