[DarthBBerry]

Did you modify any of the Roles or use the default settings?
Just used default settings. Roles not needed in our organization as I am the Supreme Overlord regarding all things BlackBerry.

Did you continue to use your existing IT Policy that was brought over, or did you switch to use one of the canned IT Policies (i.e., Basic Password Security)?
I used the IT Policy Import/Export tool in the BRK. Saved a lot of work. The canned Policies were okay, but didn't cover everything we wanted to do.

Anyone using the Individual-Liable Devices IT Policy?
Not yet, but we're considering it in the near future. I might have to edit the canned policy to suit out needs a bit.

When adding a new user, is there a way to assign the IT Policy to them at creation?
Actually, there is. If you assign an IT Policy to a group and then assign the person to the group when adding the new user.

If not, is there a way to make a specific IT Policy the one that is assigned by default?
You can also modify your Default policy to be as restrictive as you want. (Just be sure to make a copy of it BEFORE you start fiddling with it.)