Most fingerprint scanners can be fooled (Mythbusters did an episode on this). Additionally, if you are being forced to decrypt your wallet, you can claim to forget your password but you can't "forget" your fingerprints, an attacker can get hold of your fingers much easier than your password.
Right, the biometric entry is just the first level of security.
Also with the multisig, the best way to employ that would be the following:
Have the buyer and seller of the goods provide you each with a pubkey of a bitcoin address they own and generate a 2 of 3 address using their pubkeys plus yours. This way any transaction you make has to be signed by either buyer/seller so you cannot run away with the money, making it almost trust-free. Additionally it makes things easier for you as if the transaction works out OK the buyer/seller can sign the transaction themselves so you don't even need to do anything.
That's an interesting method I may implement in the future. However, there's a small learning curve for the user seeking escrow.