I like the general path that you are going with.
I would have to reiterate the ideas of KISS, and simply asking them to right down the cold hard facts of what they see, and not try to interpret it. Lets face it, numbers do not lie, unless you twist them or put an interpretation behind them.
This is a link
http://www.chiefdelphi.com/media/papers/2334? to our team's database. Being a former driver and coach, I can tell you that with information very similar to this, and knowing what each team is really capable of, you will be fine. We had a timeline of what we were to do and check every 15-20 sec during the match and change accordingly. Most of the time, we were right on from scouting (Thanks Steve - author of the database).
I was a scout my first 2 of 4 years on the team, and saw the reports go from labor intensive and lots of writing to something like this. The problem is, if the kids are writing the whole time, they are not watching the match and missing key events. I would recommend keeping it simple and looking at the numbers. The only thing left for interpretation usually is: Would we want them on our alliance?