T42 passwords and security

[zver17]

I am getting started with using the security features of a T42 (no fingerprint). However the machine was clean WinXP-formatted prior to me getting it, so I have been installing additional utilities (so far, only HDD-ASP and battery maximiser).

Is setting a HDD password preferable to power-on password (and how is it different to supervisor password), and how is it done? If possible, I would rather not have to type 3-4 passwords at every startup. Also, how do these passwords interact with standby/hibernation settings?

Also, do I need to install any security utilities (eg, "IBM Embedded Security Subsystem and Client Security Software " or the "Trusted Platform Module (TPM)") in order to achieve good security (ie, make it difficult to operate machine / access the HDD if the TP is stolen)? Also, if these programs do some encryption, does it impact on the computing speed? (which I do need as I do fair bit of code development on the TP).

thanks in advance for any help.