We were just at WL a few weeks ago. We had the "last" woods view room on the MK side in the corner of the lobby, behind the fireplace, I think it was 5081 (the first part of the wing on the MK side is standard view because it's over the service area). We were on the 5th floor and could see the fireworks from our balcony. Judging from the view we had, I would think the fireworks would be visible from just about anywhere on the MK side of the resort, 5th floor and up (possibly 4th floor, too). Note that you can't see the MK, just the fireworks over the trees. For a room request, I would think if you ask for MK side on an upper floor, you should probably be able to see fireworks.
Of course, if you're on the MK side, you can't see the water pageant from your room. There is an observation deck on the 5th floor off the lobby with a spectacular view, though!
We had no transportation problems, but did not take the busses (we were traveling with 2yo DS). We used the boat to MK several times, and never had to wait (we were just lucky). The boat does stop at FW also, though, so your trip to/from MK can be a bit long (15-20 minutes) if you end up with that stop, but your view of the resorts around Bay Lake is great, so I didn't mind the time.