Can't help with the skyline, but have been to WDW during labour day and it was really busy!
If you haven't already booked, then I would avoid that week if I was you. If you have already booked you might - if you have the time/flexibility - like to try and avoid the parks around labour day: i.e. try the beach, shopping, Everglades tour or something similar. Just a thpought.
Saying all that, it has been a few years since I have been there on labour day week: maybe current capacity controls have improved things...
Boo