In reply to:

As far as I know, Liam was never brought in for anything


Bummer.

The scene you mentioned is the only one confirmed at this point to be on the DVD. I believe Steve Sansweet revealed photos of it during the Comic-con a few weeks ago. I don't have a link handy, but I have seen pictures of that scene. As far as I know the other deleted scene content has not been anounced yet.