You folks have the right idea! If you want to watch the fireworks/projections straight on with a perfect view, there are dozens of Youtube videos for that (thanks to the fact that everybody who sees these shows seems to labor under the delusion that they're the first one to think of recording it)! The fireworks provide the perfect opportunity to enjoy attractions with a gorgeous backdrop and next-to-no lines. During Happily Ever After this past Friday, we rode 7DMT 3 times in a row, with the music, lights and fireworks adding plenty of magic.
(Full confession: We do this with parades and other nighttime entertainment, too. My family would rather skip a parade or show, and enjoy a dip in wait times, than jostle for space in the heat with the Abners of the world trying to elbow their way in.)