Oh, we'll be off to Paris while you're here!
Alas, hope you have a great trip. To answer some of your questions:
Fireworks: At the end of Main Street, just outside the photo supply shop on the right, look for a ramp that leads down from the sidewalk. Then look across the street and there will be another ramp leading up to the sidewalk on the other side. At about 30 minutes before the fireworks start, they put a rope up between these two ramps to make a walking path. If you show up about 35 minutes before show time, go to the LEFT side of the street (across from the photo supply shop) and stand just behind the ramp. There will not be a huge crowd, and once they set the rope up, there will be no one standing in front of you. And from the left side, you can see the castle, the Matterhorn, and everything else you need to see to fully enjoy the show!
Fantasmic!: Again about 30 minutes is all you need. Head around the river, towards Haunted Mansion. The walkways are tiered, stay up on the second tier. Once you're about half way around the river, just start looking for anywhere that you can see the mill building on Tom Sawyer Island. You should have no problem finding a spot. You'll have to stand, and maybe do a small amount of neck-craning. But you should have a fine view without waiting for hours.
Storytellers: Yes, make a reservation. Since you stayed in '01, they changed the way they do seating, and even if the restaurant's not busy, you could be waiting pretty long for a "standby" table. Plus, calling for the reservation gives you a chance to tell them it's her birthday without using the "I have to use the restroom" trick.