We walked around the resort last week, although you can't actually go inside.
IMHO I don't think the Epcot views will be very good. Mostly there's trees back there, and it's also along the road so there may be some traffic noise. If you get the top floor, you might see something. We'll have to wait for first hand reports on that one.
You'll probably be able to see the fireworks somewhat, especially the stuff in the sky. Don't have any idea if you'll be able to see the stuff at lake level. From our walk we couldn't tell for sure where the resort was in relation to Epcot. The large building we could see through the trees looked like the Imagination pavilion so that would put the Epcot view rooms north of Canada, so you would be looking somewhat to your right (south) to see the lake and the fireworks. I could be mistaken and the building could also have been the back of Canada or England, which IMHO would be a better view.
I think the pool view will be the best to request myself.