Pretty much the ONLY way to get a fireworks view guaranteed from your room is to book lagoon view concierge at the Polynesian.
There are fireworks view rooms at many of the resorts, but you aren't guaranteed of getting one of those rooms.
At the GF, some lagoon view rooms in Conch Key, Boca Chica, and Big Pine have wonderful fireworks views. But there is no guarantee of getting a room in those buildings, let alone one with a fireworks view.
At teh Polynesian, most of the lagoon view rooms have a firworks view, but not all. And again, you are not guaranteed of getting one of those rooms (unless as I said above, you booked concierge lagoon view).
At the Contemporary, about half the tower rooms have a MK view. The others look out over Bay Lake. There is no guarantee of getting a room facing the MK. Some of the garden Wing rooms also have a view, but not many, and in quite a few that do, the view is obstructed.
I have heard there are a very few rooms at the WL with a fireworks view, I don't know anything more. And again, it's certainly not guranteed.
You can seea little of Illuminations from some of the upper floor rooms at the AKL, I think probably the rooms in the very high 54's might have a view, but it's limited. You can also see it from the balcony area by the elevators on the 6th floor.
I've heard that a few rooms at Pop Century and the CBR might have limited Illuminations views, I don't know for sure.
At the BWI, there are some garden view rooms with Illuminations views, again, nothing is guaranteed.
At the BCV, again, there are some villas with Illuminations views, nothing is guaranteed, and these are very hard to get. (I've tried on three stays and not succeeded.)
The standard view villas overlooking Port Cochere at the BWV have limited Illuminations views.
There are a few waterview rooms at the YC and the BC that have Illuminations views, again, this is a request only.
As far as restuarants with fireworks views, the California Grill, O'Hana, Narcooses (has the best view of WISHES IMHO), Rose and Crown outdoors, the Cantina. There is extremely limited Illuminations views from some seats in Bistro de Paris, and a small handfull of tables at Citrico's have limited WISHES views.
Public places you can view fireworks from without going into a park if you aren't a guest of a particular resort would be along the path between the Polynesian and the GF, near the wedding chapel (NOT on the Polynesian beach, unless you are staying at the polynesian), and on the bridge walkway between the BWI and the BC for a view of Illuminations.
Hope this helps.
Anne