I've stayed in all the towers and views at DLH over the years, so to the best of my recollection...
Pool View will be in any of the 3 towers facing in to the pool courtyard. Downtown Disney View will be on the side of the Adventure Tower facing DTD. Anything else I believe will be in Fantasy or Frontier Towers facing away from the pool looking at city/parking lot.
The Downtown Disney View would give you the best angle for seeing the parks in the distance, but I don't think DLH markets any rooms as theme park view. I can't say for sure, but I'd imagine you'd be able to see some of the spires of Galaxy's Edge, but there is no DLH room with a prominent view into the land.
For fireworks, I don't think you'd be able to see them from any Pool View room. The best potential angle would be the Adventure Tower DTD view rooms. Some Fantasy Tower standard view (not pool) might be able to see the fireworks at an angle but I can't say for sure.