Sunday evening is great. Definitely plan on the fireworks that day.
Aladdin Show (in DCA) is a "must do" & is Wed - Sun, so you'll be able to enjoy this as well.
You'll be amazed at many of the common rides (WDW/DLR) & how often the DLR rides are different or better. Also you'll love FL (with 4-5 more rides - some old school - to enjoy).
Just be prepared for a VERY small castle....I mean you won't see it from town square....but it's beautiful & the original.
Have fun planning a visit to Walt's Park.