I also suggest the handheld captioning device - I have not tried it in WDW, but in DL it was quite helpful, especially for dark rides. It also has a sound amplification option for people who have mild to moderate hearing loss in the same device. It is well worth the trouble of stopping to get the device when you get there.
It is sometimes annoying when you know more than the CMs, but I have found that the new "Guidemap for Guests with Disabilities" was very helpful with this. It lists what accommodations are available at each attraction, like ASL, Handheld Captioning, Reflective Captioning, etc. There have been times here in DL that I have shown the map to a CM, who then had to ask a lead to help, but as long as it was done, that is what mattered. The map is much easier to handle than the old booklet.
All you should have to do is tell a CM you need to be in the front, and that should be done at each show. Make sure you tell a CM when you arrive at Fantasmic! if you want Reflective Captioning, as that is only available in one section. It will help with seating if they know ahead of time.
In Toy Story Mania, all cars are equipped with a Closed Captioning button, located below the small screen in the middle of the car. Just hit the button and you are set. I advise hitting it before pulling down the arm of the ride car - otherwise it can be hard to reach!