Can I cram everything into 2.5 days?

[HydroGuy]

Yes. Fireworks over the Castle, Fantasmic on Rivers of America. Though while many people suggest watching F! first, I don't because the view is good to ok from there. It's much better to view the fireworks from the hub area.

DL and DCA are built facing each other so it just take a minute to walk out one gate and into the other.

Totally agree with Ski here.