[Pavan Dave]

1) We had around 26 per division [13 matches in round 1, and I never got a break so it was 26 in our division]. That would put us at around 100+ teams overall though.

2) The trophies are shown for the whole tournament. With the trophies there are also FLL medals for every participant!

3) Not much. We glued some of our pieces just for that reason (the Power Lines/Grid). From my fields, there was very little field destruction. The biggest problem is with the oil barrels and those "wandering" off, but besides that it was very clean. The most damage I saw was somebody knocking the house over and the house didn't even break, it was just on its side ready to be put back on its dual lock. I would definitely glue your truck, the car, the power grid/lines, the windmill, and possibly the dam...I'll try to get the exact list of parts we glued.
4) Take a look at the video. There was minimal bumping so not many pieces fell over on their own, and the game wasn't by that for the most part.

Keep in mind some of these answers are based on my division only so it may differ for others. Overall I think mine was the most problem free, with one parent asking a question (no complaints at all), and all the kids had fun!

Any more questions?