Electrical Parade : 9 month rehab, while the Christmas Parade plays at DCA (For those going in November), along with Block Party Bash (which may only run Fri-Sun. by April, but we don't know for sure).
The rest of the times are for April:
Fireworks: Acording to the press release on May 4th will run 7 days a week throughout the 18 month long celebration.
Fantasmic, April: Fri-Sun, One show on Sun, two on Fri & Sat.
Aladdin: Dark Tues & Wed.
Yes they can and have run both Fantasmic and the Fireworks in the off season, except when something major in Fantasmic needs rehab, such as the Columbia or Elevators or the river of Fantasmic it's self, which is why we haven't seen this happen in a while.
Hours in April (Spring Break weeks excluded): DL: Fri: 9 am to Midnight (sometimes 11 PM), Sat: 8 am to midnight Sun: 9 am to 11 pm, Mon-Thrs: 10 AM - 9:00 PM (When the fireworks are running, as they are supposed to be) or 8:00 PM (When the fireworks don't run)
DCA: 10 am to 6 pm (May be extended this year to about 8:00 PM though, esp. on the weekends) and this is 7 days a week when the Electrical Parade doesn't run.
This is all based off of past experience and is how it has been for quite someitme, but due to the 50th, I would guess that you may find the hours extended.
Spring Breaks (Usually as far as Disney is concerned the Week before and after Easter, with a couple weeks before and after getting extended on a daily basis, but the above posted hours are what are posted in the morning): Same as summer hours.