Robert:
I recommend using the "GRUB For DOS"
Yes looks like another (and maybe easier) way.
Still, if you're mostly working from Linux, the most simple way is just to install grub and setup chainloaders (which is done at system install anyway). All you loos is the ThinkVantage button, no great deal IMHO.
As for hibernation, i need to clarify, it works just as usual: Grub chainloads to Windows and that just resumes. What i meant is that if you would rely on WinLogon to protect your Windows access, now there's grub with it's insecure edit and commandline escapes - which can be deactivated of course.
As i said, if you really need strong security, you wouldn't rely on either OS or BIOS side access protection, nor on any encryption, because anything can be cracked up to the point to remove the hard drive for professional analysis. You just would not store any sensitive information on such a laptop.