My family and I are staying at Bay Lake Tower through rented DVC points from Davids. WIll we be allowed into the Top of the World Lounge during fireworks?
No, you have to show a membership card to get up now. On another DVC forum, everyone ihas been reporting the same thing over the last few months. You might get lucky and they'll just scan your bands, but don't count on it. I hope you do get lucky, it is amazing.
But you can watch from the walkway to the Contemporary and the 4th floor viewing platform at the end of the walkway. Both offer decent views, with music piped in. Or head up to the Cali Grill lounge, but I don't know how early you need to go up.