Some great observations there @Desert Kris 
Touching on a point a few people have made, about perhaps opening with the TNG characters and introducing the Kirk story in flashback maybe halfway through the movie, there's another benefit of holding back on Kirk: if your main tag line for the movie is 'The Generations Meet', then keeping the trump card (ie Shatner) as something the audience has to wait in anticipation of seems sensible from a story building sense.

Touching on a point a few people have made, about perhaps opening with the TNG characters and introducing the Kirk story in flashback maybe halfway through the movie, there's another benefit of holding back on Kirk: if your main tag line for the movie is 'The Generations Meet', then keeping the trump card (ie Shatner) as something the audience has to wait in anticipation of seems sensible from a story building sense.