If you were to remove Q from every shot in the movie, you'd find that the plot wouldn't really change at all. The Q plot was indeed padding and had no affect on the main plot of the episode. I think the whole "humanity on trial" only gains more credibility and dramatic effect because of the way Braga & Moore cleverly used it in to bookend the series in "All Good Things". Otherwise, here it was just something to add an extra 30 minutes and an excuse to introduce the saucer separation.
I completely agree with this. At one point, IIRC, Picard even says they will going on doing what they are doing to the bitter end. This idea basically establishes that even when threatened, the Humans will continue to do the same thing because they are doing the right thing - a key element of TNG. Add the bookend finish and suddenly the throw-in Q plot becomes a pretty nice touch.