PP has a number of rooms that sleep 5 - two queen beds and a daybed. We had one earlier this year, but I think a lot of them are like that.
I'm not sure about views for the fireworks...actually, I think the rooms that might have the best views would be standard view rooms at the DLH in the Magic (formerly Marina) tower that overlook the hotel entrance/parking lot! I'd think you should be able to see them from park view rooms in the Dreams (Sierra) tower, though. At GCH it's the Downtown Disney view rooms that have the best chance of having a fireworks view. At the PP, I don't think you'd be able to see them from the park view rooms closest to DCA (e.g. those that have the best DCA view), but you should have a view of them from those that are on the north end of the hotel that look more towards the GCH.