Here's a video of Symphony in the Stars from last years May the Fourth event. It should be the same show or very similar to this:
http://www.youtube.com/watch?v=EiQCpsOmh_k
As for what the best location is to view them; if you want to have the Hat centered with the show then anywhere down Hollywood Blvd. Do not go to close to the Hat or you will lose some of the fireworks, I would say from the tip board down to the main entrance is fine.
If you don't mind not having the hat in the center then around Echo lake is a good alternative. By the Indy theater is a good place and you can sit in the stair around there. We always watch the special events fireworks from DHS (July 4th, NYE) from a bench next to 50s Prime Time, it's obviously not centered but it's better than battling the crowds down Hollywood Blcd.
Do not watch them from Sunset Blvd, there are bldgs and tress that will block you.
I haven't watched them from the back of the park (Streets of America/Backlot Area) but you should be able to see them fine since the fireworks are launched from a top of The Great Movie Ride and from the backstage areas of Backlot Tour
I guess I'll have another excuse to stay late every night to see them from different angles and report back

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Sorry Reizo I didn't realize you had already posted a link to the fireworks