1) To rebuild my DT, I no longer had to hold down command/option during boot. I just have to press them immediatley after hitting the OK button to log in. I am not sure if this affects all user accounts or only the account you are logging into.
I had an issue w/ rebuilding the DT where my DT printers came up w/ an X through them. I trashed them and went to re-create them but I was not able to. The Chooser still thought they existed on the DT. After rebuilding the DT again, trashing finder prefs, zapping PRAM and a few other tricks, it turned out that I also had to trash the Printers from the guest account I had created. Once I did that, I was able to rebuild my DT printers.