I'm sorry but this is all crap. No matter what you say physical acess==it is not your computer anymore. All your protections are BS. Some one that is prepared and ready to get make your machine turn against you will accomplish that with physical acess. Forget your BS about your bios passwords, encryptions etc; some one prepared to take you machine over can simply install a hardware keylogger. Hell, depending on the money availabe to the group and willingness to keep at it until they get it, they don't even need to put a device on your machine: ever here of electromagnetic analysis of the different keys or acoustic cryptoanalysis?

Nothing short of a computer that never connects to the outside world (even through removable media) and creation of a system that is 100% effective against physical accesses and passive EM and acoustic analysis will secure you computer. But then, what the hell is the point you no longer have a really usable machine.

For a usable machine for the home user (not state secrets, confidential material, etc) the best advice is:

1) limit physical acess to your computer
2)use encryption to encrypt your computer (with a separate home partition you can set separate passphrases to boot into linux and to mount your home partition)
3) shut down computer if you have to leave it unattended
4) if your computer has been out of your sight for quite a while, inspect it for tampering, including opening it up if you feel it necessary
5) if you are only worried about very specific files, use something like TrueCrypt to create an encrypted folder that is only decrypted for use and re-encrypted as soon as the use is over

Other advice: don't bother with the fingerprint readers unless they have become MUCH better. The myth busters beat some commertial grade fingerprint readers for very reputable companies and beat it with a photo copy that was like and placed on thumb to mimik real "life" signs.