Welcome, I would urge you to carefully consider towing that size trailer with an SUV. At 33' and a gvw of 9,650 lbs plus 4 teenagers? I think your Ecpedition will be grossly over weight. At a tongue weight of 15% of gvw that's a 1,447 lbs. Add another 100 lbs for a weight distributing hitch and your loading 1,550 lbs just on the hitch which likelly exceeds the hitch rating.
Add the weight of your DW, 4 teens, and all their gear and you're likely 2,500 lbs at a minimum. Payload, found on the tire inflation chart on the driver's door is the number of concern. Max towing numbers mean nothing as you will exceed payload capacity long before you reach that max towing number.
2012 Laredo 303 TG
2010 F250 LT Super Cab, long bed, 4X4, 6.4 Turbo Diesel