There is a balcony. It only overlooks the entrance to YC and the parking lot. I didn't try watching Fws from it so I can't help you there. It didn't appear that it had a great view of any of the parks.
The construction going on at the concierge, and expansion of the lounge area, there might be a better or different view. If they are just making larger the existing area, then the view will still be of the entrance drive and gardens, and no fireworks are visible from that area.