I was there for Star Wars Weekend for two days and stood in two places for the fireworks on two different nights.
The first night we found a small 'bump out' walkway area into Echo Lake across from Min & Bills (the back side). It walk way is directly across from the 50s Prime time. That area had a great view of the fireworks, a planter bench to sit on while we waited, and then to stand on for the DS8 to see better. The only complaint was that the music wasn't as loud as I like fireworks music to be. But it allowed us to be a little farther away - and therefore take in the full show in the sky in one view.
The second night we had the dessert party section which was very close to the hat stage. This area was nice and loud for the music, but the fireworks were a bit obstructed by the hat, the trees, etc. Don't get me wrong, good view just very close.
I feel like that would also be true anywhere on the street as well - but for Hollywood Studios, that's part of the experience - having the street and the hat as part of the show - like the castle at MK. But if you just want to see the fireworks - then check out the walkway by 50s. The fireworks go directly over the Min & Bils boat when you look across the lake.
Of the two, I would go back to the walkway by 50s.