Highlighting where to hit would be huge. A green smoking flare would be pretty cool.
In general - it would be nice to be able to put up a banner message in TB, HAAT, and Pit that was persistent. and always there.
That way the single spot for the Banner on the Guild Chat could be used for communicating other information.
And yeah, +'s for being able to see who DIDN'T participate in something. I don't believe there is much strategy in TB, it just comes down to GP really, so we need to be able to talk/drop people in an informative way.