I'm curious about the fleet myself. Usually things this big happen on TV (and often backstage at that) rather than in the movies. When the fleet was lost in 'The Best of Both Worlds part 2' it was a really big deal. STVI: The Undiscovered Country is probably still the most 'epic' ST movie in terms of 'narrative' scope, and even it pales in comparison.
One of the more valid criticisms of JJ's last movie is that, for all its 'visual' scope, it appears to take place in a shrunken universe that is happily uninformed regarding speeds and distances. Would blowing up most of a starfleet counter this perception or reinforce it? Haw big a canvas would the director work with in doing something like this?