Question regarding filevault and a honeypot account

Question

I am running osx lion.  I would like to secure my machine, and that includes basics like good passwords and turning on a firmware password.  But I would also like to encrypt the contents of the hard drive.  Filevault to the rescue it would seem.
But I also have one more requirement.
Since a lot of my equipment was stolen last year I have installed prey on all of my new computers (www.preyproject.com).  This allows me to track my machines and potentially get them recovered should they go missing.  Prey is useless unless there is a user logged in and so I have created a honeypot account that is minimally protected (i.e. the password is the user name and the password hint explicitly tells you what the password is).  This account has parental controls on it to limit the applications that can be run (only web browser, some games, and skype).  The idea is that a dumb thief steals my computer, finds it easy to log into the honeypot account, and then uses that with their facebook or whatever because getting past the open firmware settings and the individual "real" account passwords is too hard.
That said, having this software is no guarantee that I will be able to recover my machine, so I want my data encrypted.
Here is my question:
Does the fact that I have to add this simple password for the honeypot account to use the computer (aka open a filevault drive) invalidate my filevault protection?  I.e. will this simple password allow them to unencrypt the entire drive, even though I have other accounts with stronger passwords?

Answer 1

The guest account might be just good enough...  I'll give it a try.  Thanks.  Prey seems to work pretty well for me but it has also been touchy in the past.  I will have to check it carefully with the guest account to ensure it has the permissions needed to use the webcam and send email and such.
I'm still interested in knowing how filevault encryption works.  Does it allow any of the passwords to unencrypt the whole drive, or does it require a unique password per account to unencrypt the data in that account?
Edit:  Just saw the repy by Linc Davis
"If everything worked perfectly, the account would only have access to the files in its home folder. But is there an unknown exploit that enables a local user to gain elevated privileges? Such exploits have been found in the past, and may be found in the future."
That clears it up for me a bit.  And it makes sense.  I will see if I can make do with the guest account.
That said, I actually value the computer hardware - though not as much as the data.  I already back the data up which is the first step.  Preventing others from accessing it is my next priority, but there is nothing that is THAT critical.  I can change all my passwords quickly (and I don't use anything like 1password).  I have tax returns on the drive, but they are also password protected.
My primary goal is to keep the average and even slightly above average user from getting to my data (including yanking the drive and putting it into another machine or booting from a CD).  As I said, I hope the guest account will be adequate for my honeypot needs.
Also @Linc,
I accidentally clicked on "Helpful" instead of "Answered" on your post.  Post a reply and I will do it right this time.  Thanks.
Message was edited by: Bernhard VonZastrow1